[clang] [Clang][ByteCode][NFC] Misc minor performance fixes (PR #145988)

[Shafik Yaghmour via cfe-commits]

shafik wrote:

Looks like the window CI fail is related to this issue: https://github.com/llvm/llvm-project/issues/145703

https://github.com/llvm/llvm-project/pull/145988