This PR moves attrs.h into the ir folder as it
can serve as a common infra for building ir dats structures.

We also moved common container(FloatImm) into ir/expr.h

This PR moves a few base types from relay and low-level Expr into the ir sub-folder.
These classes will serve as a common type system across the stack.

Rationale:

- PrimExpr for low-level expressions
- RelayExpr for advanced features, including Function definition.
- Introduce BaseFunc to host all functions, including future PrimFunc(low-level expr functions, subject to discussion).

This is a minimum change we can do to unify the classes into a common hierarchy.
The main data structure that are variant specific will still be kept in the sub-namespaces.
We only include classes that is needed to allow a common Module class.
- BaseFunc
- GlobalVar
- Type definition part of ADT

We will only need the BaseFunc and their checked_type to decide the calling convention
across the function variants.

* [REFACTOR][OBJECT] Consoldiate NodePtr/Ref/Hash/Equal and macros to Object.

Historically, we have classes like NodePtr/Ref/HashEqual.
After unified object protocol, these names are just alias of the object counterpart.
Moreover, there are helper macros defined over the places for defining these object.

This PR consoldiate the terminologies into the corresponding ones
in the Object system so we have a clean and consistent API moving forward.

* Update include/tvm/attrs.h

Co-Authored-By: Wei Chen <ipondering.weic@gmail.com>

* fix compilation

Co-authored-by: Wei Chen <ipondering.weic@gmail.com>

* [NODE][REFACTOR] Refactor reflection system in node.

- Removed the old Node, Node is now just an alias of runtime::Object
- Introduce ReflectionVTable, a new columnar dispatcher to support reflection
  - This allows us to remove vtable from most node objects
  - The VisitAttrs are registered via TVM_RESGITER_NODE_TYPE,
    they are no longer virtual.
- Consolidated serialization and reflection features into node.

* Explicit type qualification when calling destructor.

* Fix SPIRV, more comments

* [REFACTOR][NODE][RUNTIME] Move Node to the new Object protocol.

This PR removes the original node system, and make node as a subclass of Object.
This is a major refactor towards a better unified runtime object system.

List of changes in the refactor:

- We now hide data_ field, use Downcast explicitly to get a sub-class object.
- Removed the node system FFI in python.
- Removed the node C API, instead use PackedFunc for list and get attrs.
- Change relay::Op::set_attr_type_key(attr_key_name) to relay::Op::set_attr_type<AttrType>().
  - This change was necessary because of the new Object registration mechanism.
  - Subsequent changes to the op registrations
  - The change revealed a few previous problems that is now fixed.
- Patched up a few missing node type registration.
  - Now we will raise an error if we register object that is not registered.
- The original node.h and container.h are kept in the same location.
- Calling convention: kObjectHandle now equals the old kNodeHandle, kNodeHandle is removed.
- IRFunctor now dispatches on ObjectRef.
- Update to the new type checking API: is_type, derived_from are replaced by IsInstance.
- Removed .hash member function, instead use C++ convention hasher functors.

* Address review comments

* Getting closer to having ADT defs

* ADT defs working probly

* Match parsing basipally done

* came to earth in a silver chrome UFO

* match finished?

* All tests but newest are passing

* ADT constructors work

now cleanup?

* Cleanup round 1

* Cleanup round 2

* Cleanup round 3

* Cleanup round 4

* Cleanup round 6

* Cleanup round 7

* Lil grammar fix

* Remove ANTLR Java files

* Lint roller

* Lint roller

* Address feedback

* Test completeness in match test

* Remove unused imports

* Lint roller

* Switch to Rust-style ADT syntax

* Lil fix

* Add dummy `extern type` handler

* Add type arg to test

* Update prelude semantic version

* Repair test

* Fix graph var handling in match

* Revert 's/graph_equal/is_unifiable' change

* implement tuple pattern

* add tuple pattern

* lint;

* lint

* lint

* fix error

* fix

* add test

* add fatal

lint

lint

lint

do

make completeness check an error

lint

remove fatal

* fix test

* reset parser file

* remove unneeded import

* Update python/tvm/relay/adt.py

Co-Authored-By: Steven S. Lyubomirsky <slyubomirsky@gmail.com>

* Update include/tvm/relay/adt.h

Co-Authored-By: Steven S. Lyubomirsky <slyubomirsky@gmail.com>

* Eliminate trailing whitespace (my fault)

* First pass at Relay-to-Python converter testing utility

* Indicate astor as a dependency

* Add astor dep to host as well

* Typos and small bugs

* Handle ADTs and matching in Python conversion

* Remove any dependency on ast.parse

* Eliminate unnecessary type var field in Python version of ConstructorValue (already gone on C++ side)

* Update constructor value, fix syntax errors

* Don't forget keywords arg on Call nodes

* Fix some incorrect calls to ast nodes

* Fix more calls, a little more cleaning up

* Missing cases in attr conversion

* Lower op calls instead of running them through interpreter, as in @MarisaKirisame's AoT compiler

* We do still need the module

* Remove changes to op attrs: Will PR separately

* Smoke test and corrections

* More tests and fixes

* Ensure imports are properly global in generated Python code

* Add unit tests for refs

* Add unit test for tuple indexing

* Add unit test for if expression

* Remove astor dependency

* Remove astor from meta.yaml too

* Fix if test and add basic local function test

* Add global function test, refactor earlier tests

* Correct 'clause' field in ADT so Python and C++ field names match

* More fixes and tests for matching and constructors

* Dramatically simplify matching: no need for a thunk

* Improve ref writing test

* Ensure local recursion works

* cleanup

* Add test for global recursion

* Add test for higher-order calls

* Get ops working, add basic tests

* Remove accidentally duplicated test

* More docstrings to appease pylint

* Forgot to fix a test using constructor values

* Reduce optimization level in fusion and fix tuple input to operators

* Test op with tuple output, fix tuple output code

* Add unit test for batch norm

* Add a couple more tricky test cases

* Correct nat constructor to drop unnecessary field

* Fix the op attrs file (accidentally reduced it)

* Address review comments

* Adapt to new ConstructorValue representation (no more runtime dep on module)

* Use pass manager and updated interfaces. Extend module.from_expr to accommodate necessary demands

* Use sequential return value

* Lift out nested conditionals

* Replace triple single quotes with triple double quotes

* Use main variable instead of entry_func

* Use hash of ADT name and constructor idx to generate tag, add reverse mapping to module and use where appropriate

* Lint and build fixes

* Add round-tripping test for getting constructors by tag

* Use int64_t everywhere for tags

* Add additional identity check

* Bring out _arg_to_ast again

* Use 8-bit hash of GTV name as MSB of tag, index as LSB for more readable tags

* Use int32 instead of int64 for tag

* [HEADER] ASF header dir=include

* [HEADER] ASF Header dir=src

* [HEADER] ASF Header -dir=python

* [HEADER] ASF header dir=topi

* [HEADER] ASF Header dir=nnvm

* [HEADER] ASF Header -dir=tutorials

* [HEADER] ASF Header dir=tests

* [HEADER] ASF Header -dir=docker

* fix whitespace

* [HEADER] ASF Header -dir=jvm

* [HEADER] ASF Header -dir=web

* [HEADER] ASF Header --dir=apps

* [HEADER] ASF Header --dir=vta

* [HEADER] ASF Header -dir=go

* temp

* [HEADER] ASF Header --dir=rust

* [HEADER] Add ASF Header --dir=cmake

* [HEADER] ASF Header --dir=docs

* [HEADER] Header for Jenkinsfile

* [HEADER] ASF Header to toml and md

* [HEADER] ASF Header to gradle

* Finalize rat cleanup

* Fix permission

* Fix java test

* temporary remove nnvm onnx test

* First pass on ADTs

* Add doc string for tag field

* Visit constructors in TypeVisitor for TypeData

* Add to description of type call

* Add type call to type solving and unification

* Make type mutator for typecall consistent with others (only create new node if there's a change)

* Ensure kindchecking can handle type calls and typedata

* Fix bad nesting in module constructor

* Correctly construct call in typecall test

* Add call override for ordinary vars (do we want this?)

* Remove generalization hack from type inference because it was breaking ADT constructors

* Check that there are no free type vars in exprs after inferring type

* Free var checks need module because of ADT constructors

* Typecall test can't have unbound type var, make it global

* Uncomment tmap test and remove comments about failing to infer ret type; those work now

* Put in dummy visits for ADTs in graph runtime codegen to placate pylint

* Fix Relay type infer test module constructor

* Mark override for TypeCallNode in type solver

* Ensure free vars check treats patern vars as bound

* Run interpreter in more ADT test cases

* Refactor kind check to return the kind, like typechecking

* Fix invalid typecall in test

* Add kind check to type inference, do not use nulls in func_type_annotation()!

* Redundant whitespace

* Make TypeData a separate kind

* Make ADT handles a separate kind too, document calling convention better

* Remove nats and tree from prelude, move to test, document prelude

* Restore and document nat and tree to prelude, add more tree tests

* Add alpha equality tests for match cases, fix variable binding bug

* Add more kind check tests for ADTs

* Add more tests for finding free or bound vars in match exprs

* Add unification tests for type call

* Update main() for alpha equality tests

* Add simple type inference test cases for match exprs and ADT constructors

* Add more ADT interpreter tests

* Allow incomplete types when typechecking match cases

* Type inference for pattern vars should use the type annotation if it's there

* Two more specific test cases for ADT matching

* Add option ADT to prelude

* Fix broken reference to kind enum

* Fix rebase snags

* Do not attach checked types to constructors

* More docstrings for module fields

* Use proper wrapper for indexing into module type data

* checked_type for constructors is not populated

* Expand type call docstring

* Rename PatternConstructor con field

* Use error reporter for pattern constructor case

* Condense error reporting in kind check, use error reporter

* Expand docstrings and rename ADT fields

* Rename 'option' ADT to 'optional' for consistency with Python

* Add various list iterators and utility functions to prelude

* Add smoke tests for new iterators in prelude

* Add concat to prelude

* Add smoke test for concat

* Correct docstrings in prelude

* Ensure that type defs are written in module initialization

* Various requested renamings

* Correct rebase snags

* Add kind check tests for ref types

* Update the main() for kind checking tests