[analyzer] Add support for more invalidating functions in InnerPointerChecker.
According to the standard, pointers referring to the elements of a
basic_string may be invalidated if they are used as an argument to
any standard library function taking a reference to non-const
basic_string as an argument. This patch makes InnerPointerChecker warn
for these cases.
Differential Revision: https://reviews.llvm.org/D49656