[nnc] Separate printing of optimized llvm bitcode from assembly (#56117)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/56117
I was debugging an issue during instruction selection and wanted to
see the input bitcode. This way we always print it before going into the asm
generation pass.
ghstack-source-id: 126592596
Test Plan: Run with `PYTORCH_JIT_LOG_LEVEL=">>llvm_codegen"`
Reviewed By: huiguoo
Differential Revision: D27781683
fbshipit-source-id: 84635d0ca2a1318ae7a9a73cc1d2df450d8b6a08
