This deprecates the use of release-build LLVM hosted by the LLVM project, which makes debugging harder for developers.
This PR implements the following solution:
1. Create LLVM release tarballs with assert enabled on our own (using Docker)
2. Host them in our own GitHub repositories
3. Use our LLVM for CI and/or development if `TRITON_USE_ASSERT_ENABLED_LLVM=1` is set.
Add backend support of arith::AddIOp, arith::AddFOp, GetProgramIdOp, GEPOp and bugfix for SplatOp, StoreOp, FuncOp
Co-authored-by: gzhu <gzhu@nvidia.com>
