[llvm] [DirectX] Fix DXIL part header version encoding (PR #91506)

[S. Bharadwaj Yadavalli via llvm-commits]

https://github.com/bharadwajy commented:

I see failures of LLVM regression tests (target `check-llvm`) with these changes.

Total Discovered Tests: 59475
  Skipped          :   346 (0.58%)
  Unsupported      : 27503 (46.24%)
  Passed           : 31174 (52.42%)
  Expectedly Failed:    63 (0.11%)
  Failed           :   389 (0.65%)
FAILED: test/CMakeFiles/check-llvm /workspace/github/oss/llvm-build/hlsl/Debug/test/CMakeFiles/check-llvm 

No such failures without this change (i.e., commit set to 8d9b15497d70ac782d7d01a2d606f9fec7e7f642) 

Total Discovered Tests: 59474
  Skipped          :   346 (0.58%)
  Unsupported      : 27503 (46.24%)
  Passed           : 31562 (53.07%)
  Expectedly Failed:    63 (0.11%)

Failures appear to be related to changes in `llvm/tools/llc/llc.cpp`

Please double check. Thanks!

https://github.com/llvm/llvm-project/pull/91506