[libc++] [LIBCXX-DEBUG-FIXME] Iterating a string::iterator "off the end" is UB.

The range of char pointers [data, data+size] is a valid closed range,
but the range [begin, end) is valid only half-open.

Differential Revision: https://reviews.llvm.org/D101676

GitOrigin-RevId: 12dd9cdf1a8267e0c5db4f191f2598648de02619
1 file changed