[CIR] [Fix] W64 Compiler error for std::max (#174519)
In W64, size_t and ul are different sizes. So, std::max cannot correctly
deduce the operator type, resulting an error at compile time.
The fix was originally added in
https://github.com/llvm/llvm-project/pull/173802, but as suggested it's
best to keep unrelated changes separate.
