<optional>: Add Address Sanitizer annotations

[ozguronsoy]

When optional is empty the internal storage is poisoned, it's unpoisoned when a value is assigned.

• Added _ANNOTATE_OPTIONAL, _DISABLE_OPTIONAL_ANNOTATION, etc. to __msvc_sanitizer_annotate_container.hpp.
• Added poisoning storage in _Optional_destruct_base on empty construction and reset.
• Added unpoisoning of storage in _Optional_construct_base::_Construct.
• Added poisoning and unpoisoning tests.

Resolves #5974

[ozguronsoy]

@microsoft-github-policy-service agree

[frederick-vs-ja]

I think there should be a concentrated controlling macro for these.

[ozguronsoy]

I don't think it's necessary since this check is only done here. I also added defined(_INSERT_OPTIONAL_ANNOTATION) to the check.

[ozguronsoy]

Hi @StephanTLavavej, since the <flat_map> and <flat_set> have landed, can we move on with the review when you are available?

[StephanTLavavej]

Yes, I'm trying to get through my PR review backlog. I know you've been waiting a month, for which I apologize. I'm the only maintainer flying this jumbo jet at the moment, so I ask for your patience!

[ozguronsoy]

Wow that must be tough. It's no problem, I can wait.

[davidmrdavid]

Left some very minor feedback. The implementation seems sound, but from comparing the test matrix to the one in the asan vector and asan string annotations, I suspect we'll need a few more scenarios. I'll defer to @StephanTLavavej as usual.