* Fix Python docstrings

* More fixes

* Fix lint

- Move the related files to tvm.te
- Move build_module.py to tvm.driver

- Move related files into the corresponding location as in C++
- Keep the top-level TVM API backward compatible to make minimum changes in topi

* [REFACTOR][PY] Establish tvm.runtime

This PR establishes the tvm.runtime namespace that contains the core runtime data structures.
The top-level API are kept inact for now via re-exporting.

We will followup later to cleanup some of the top-level APIs.

* Fix ndarray name

* [REFACTOR][PY] tvm._ffi

- Remove from __future__ import absolute_import in the related files as they are no longer needed if the code only runs in python3
- Remove reverse dependency of _ctypes _cython to object_generic.
- function.py -> packed_func.py
- Function -> PackedFunc
- all registry related logics goes to tvm._ffi.registry
- Use absolute references for FFI related calls.
  - tvm._ffi.register_object
  - tvm._ffi.register_func
  - tvm._ffi.get_global_func

* Move get global func to the ffi side

* replace TensorObj and TensorValue with NDArray

* NodeBase to Object in Python

* rebase

* [REFACTOR][IR] tvm::Expr -> PrimExpr(Primitive Expr)

As part of unified IR, we will need to unify relay::Expr
and the current tvm::Expr under the same base type.

From the techinical point of view. tvm::Expr is a "primitive"
expression that only contains POD types and handles and does
not do life-cycle management.

This PR renames Expr->PrimExpr to clarify that.
We will send a subsequent PR to introduce the base expr class.

* Remove legacy VarExpr and ExprHash/Equal

* [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

* Defined a common base class for TensorComputeOp and ComputeOp

* Made changes requested by @ZihengJiang

* added a testcase to assert that `tensorize` does not have any effect on TensorComputeOp ops.

* move layout.h & layout.cc from relay to tvm

* change ConvertLayout in relay to bijectiveLayout->Forward/backward

* add first test case

* add LayoutAxis

* add LayoutAxis struct and compiles

* simplify BijectiveLayout rule consturct

* polish func name for Layout, move impl to .cc, remove Layout::defined(), add defined() checker

* partially add layout py support

* add layout test cases

* add doc for tvm.layout & tvm.bijective_layout

* fix lint

* fix lint

* fix layout name generation bug

* fix layout typo

* address comments and add topi.layout_transform

* layout.h->data_layout.h, test_lang_layout.py->test_lang_data_layout.py

* on the way to enable hybrid schedule

* I think I am done with imperfect loop split?

* copyright watermark

* loop annotation

* fix lint

* fix lint 1

* shit!

* loop reorder supported

* support bind to add some tests

* fused tested

* imperfect loop testcase

* fix lint

* add bind testcase

* fix doc

* fix online edit typo

* resolve @mercymercy review

* fix indent

* i should convince myself it is not flaky test first

* fix test hybrid

* how many flaky test are you expecting; i ball ball u to let me pass

* rebase halide...

[HYBRID FRONTEND] Modify hybrid script to new interface; hybrid op supported; enable compilation_database in CMakeList.txt (#1757)

* Support rank-0 tensor

* fix lint

* [PYTHON/FFI] Enable Cython FFI

* fix cython

* [LANG/CODEGEN] Intrinsics and Extern Math

* fix lint

* [DOC] Scan tutorial

* Fix according to ziheng's comment

* [DOC] API doc organization.

* remove breathe for now

* [DOC] Initial doc system

* Migrate API

* Update docs

* [OP/LANG] Support Extern Call, more regression tests

* [TEST] Include pylintrc

* [LANG] Include buffer semnatics, introduce pylint

* Refactor inline add support for buffer indexing

* fix doc

* [PASS] Schedule Ops init working version

* bugfix in PassUp