Fix an issue in the special snowflake windows version of the STL

[barcharcraz]

We change the size of critical sections based on _CRT_WINDOWS, but that macro is defined at build time only, and the size is relevant in our headers. We need to change the size based on UNDOCKED_WINDOWS_UCRT as well, which is defined in consumers.

I've added a pragma detect mismatch as well, but as its own commit. If we don't want it we don't have to accept that commit.

[CaseyCarter]

The build is failing with "C4384: pragma detect_mismatch should should only be used at global scope" which seems bogus to me. I suggest that you suppress the warning, verify that the detect_mismatch is correctly emitted into object files, and report the bogus warning to the compiler folks. Failing that, I suppose we'll have to have a separate conditional outside of the class scope just for the detect_mismatch.

[barcharcraz]

The build is failing with "C4384: pragma detect_mismatch should should only be used at global scope" which seems bogus to me. I suggest that you suppress the warning, verify that the detect_mismatch is correctly emitted into object files, and report the bogus warning to the compiler folks. Failing that, I suppose we'll have to have a separate conditional outside of the class scope just for the detect_mismatch.

eagh, it is a bit shifty to have pragma detect mismatch in the middle of a class definition, I'll just move it

STL reviewed this and casey's comments were addressed