* Support for batch ComputeOp

* Support for batch ComputeOp

* Fix CrossThreadReduction

* Fix lint

* Add UpdateArray, remove support for batch reduce

* Tuple input support for reduce

* rfactor works with multiple reducer; support multiple reducers with different types

* Small fix

* Small fix

* Change return type of rfactor to Array<Expr>

* Fix lint

* Improve

* Add tutorial

* Improve tutorial

* Improve tutorial

* [BUILD/CODEGEN] Allow combine multiple functions in build stage.

* Enhance code module

* fix compile

* [CODEGEN/RUNTIME] Metal support, runtime improvement.

* Fix case when no device is available

* [LANG] CommReducer

* Reorganize c_api

* Remove InitValue and Combine; refactor Functor

* Make CommReducer an Expr

* Make comm_reducer type independent

* Make CommReducerNode a Node

* Small fix

* Refine

* Refine front api; add integration testcases for min/max

* Fix python

* Refine

* Fix lint and add example

* [PERF] Add gemm

* [DOC] Reduction tutorial

* [PERF] Persitent kernel

* fix doc

* [LANG/GPU] Cross Thread Reduction.

* Fix doxygen error

* Upgrade verilog testcase to new one