This reverts commit 224cc243.

As GraphRuntime does not provide control-flow logics, we have to split
our model to two parts. While we need to share parameters between them
to save memory usage.

Solution:
1) add "lazy_init_input" in graph's attributes
   "attrs": {
     ... ...
     "lazy_init_input": [
       "list_str",
       [
         "p0"
       ]
     ]
    }
2) allow un-allocated NDArray entry in SetupStorage
3) utilize "set_input_zero_copy" function to set parameters

* heterogeneous build for c++

* merge relay buildmodule to codegen build

* use module split

* use target_host

* remove sse3

* retrigger ci

* [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

* Make python BuildConfig serializable/deserializable to/from string

* Make C++ BuildConfig serializable/deserializable to/from string

* Revert "Make python BuildConfig serializable/deserializable to/from string"

This reverts commit a5e1fb3ff63a161cc0d63475d2a32816cc4c3666.

* Revert "Make C++ BuildConfig serializable/deserializable to/from string"

This reverts commit ec0c2c54543050fe6f264d06eebff33dee70370b.

* Converted BuildConfig to use TVM node system

* Fix lint

* Fix lint

* Added code to set node attributes through the C API

* Fixed bug in build_config()

* Fix lint

* Fix lint

* Fix test errors

* Reduced scope of node __setattr__ to apply only to BuildConfig

* Fix lint

* Fix lint

* Changed python BuildConfig to be immutable, with values set once on construction.

* Fix lint

* Fix C++ test

* Fixed BuildConfig setting python-side args

* Fix lint

* Removed dependency on reflection.cc to construct BuildConfig (allow use in runtime library)

* Fix lint

* Revert "Fix lint"

This reverts commit 16ed6d7a1ca5e551b035bad46e8361ea487cd45b.

* Revert "Removed dependency on reflection.cc to construct BuildConfig (allow use in runtime library)"

This reverts commit 43817c97a2ee045791e0c031d962fa97636ce8f6.

* Avoid accessing BuildConfig when using runtime lib

* Fix missing import

* Fix error running under cython (root cause: node handle is not valid until after __init__ has returned, so cannot call __dir__ during __init__

* Fix error where BuildConfig._node_defaults was not copied in build_config()

* Fix lint

* Fix lint

* Fix lint

* Fix lint

* Add comments to python BuildConfig

* Port build_module.py to C++

* Fix lint errors

* Fix more lint errors

* Fix more lint errors

* Fix more lint errors

* Fix build error

* Implemented style fixes

* Fix lint errors

* Added function to construct target from string
lower now returns array

* Fix lint error

* Implemented review changes - style & Target options -> std::vector

* Fixed lint, argument alignment and added unit test

* Changed test to target LLVM, fixed sign compare warnings

* Reverted unit test to CUDA, changed Jenkinsfile to enable GPU for C++ tests

* Slight change to Jenkinsfile

* Changed build_module test from CUDA to LLVM

* Added function var() to construct a Var instance.
Changed implementation of LLVMEnabled()

* Reverted Jenkinsfile