[TensorExpr] Add LLVM codegen. (#34228)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34228
This PR adds LLVM codegen to tensor expressions. LLVM is added as an
optional build dependency specified with `USE_LLVM=<path_to_llvm>`
variable. If this variable is not set or LLVM is not found in the
specified path, the LLVM codegen is completely disabled.
Differential Revision: D20251832
Test Plan: Imported from OSS
Pulled By: ZolotukhinM
fbshipit-source-id: 77e203ab4421eb03afc64f8da17e0daab277ecc2
Author
Mikhail Zolotukhin
