[DirectX] Reapply Fix DXIL part header version encoding (#91956)

This reapplies
https://github.com/llvm/llvm-project/commit/195d8ac26d91ca798733c3a5f58d67992d43503d
[DirectX] Fix DXIL part header version encoding. The endian issue was
fixed by
https://github.com/llvm/llvm-project/commit/f42117c8517cc928c6373bad35ebf75d94fe865b.

Move MinorVersion be the lower 8 bit.
Set DXIL version in DXContainerObjectWriter::writeObject.

Fixes #89952