* integate cast_simplify into ir_simplify

* fix cast simplify testcase

* Clarify cinn/ir dirs [Part1]

* addition of cinn/ir/op dir

* change header inludsion of ir/ir_operator.h to ir/op/ir_operator.h

* merge with develop changes

* relocate libschedule_desc_proto.a

* remove extra ir_schedule_error.cc

* addition for schedule/ir_schedule_error files

* feat(cmake): add cmake of cinn

* feat(cmake): add cmake of cinn python test

* feat(cmake): add jit

* feat(cmake): test/CMakeList.txt

* feat(cmake): rebase to develop

* feat(cmake): remove some flags

* fix(cmake): fix cinn's gflags depends

* feat(cmake): add ci scripts of cinn

* feat(cmake): copy code of cinn

* fix(cmake): fix cinn third_party model path

* gflags dynamic dependce

* fix ci build_demo

* tmp update to c++17 of cinn-only test

* fix cinn only with c++17