<vector>: Annotate vector for use with ASan

[cbezault]

ASan can be taught to understand the concept of an access to a contiguous container that is in a valid region of memory but not in a valid region of the container.

e.g.

std::vector<int> v;
v.push_back(1);
v.pop_back();
*v.data() = 1;

would not result in an ASan exception as things stand. However, we can add annotations to the ASan shadow memory using __sanitizer_annotate_contiguous_container which will allow ASan to detect the invalid access.

[AlexGuteniev]

• <string> ?

[StephanTLavavej]

Linking #2071 (comment) here for the record - <string> changes are indeed planned.