/std:c++latest implies /permissive- but not /Zc:preprocessor, so we have to manually enable it.

• Build the STL, benchmarks, and validator with the conformant preprocessor.
  • I've verified that the compiler option is active in each directory.
• Drop "we use SAL annotations" comment.
  • This was added by add format target to cmake #2671 on 2022-05-01, then _Printf_format_string_ was removed by Modernize validate.cpp: Use <print> instead of <cstdio> #3919 on 2023-08-03.
  • We can keep using /analyze, though. It adds ~4.5 seconds on my machine, but it's not part of the dev inner loop, and Code Format Validation isn't on the critical path (the Early Builds take longer).
• Use _wfopen_s() instead of defining _CRT_SECURE_NO_WARNINGS.
  • Also avoid crashing in ~BinaryFile() if the file wasn't successfully opened.
  • Note that m_file already has a data member initializer, so it's null before we call _wfopen_s().