[libcxx-commits] [libcxx] [libc++] Use __wrap_iter in string_view and array in the unstable ABI (PR #74482)

[Louis Dionne via libcxx-commits]

ldionne wrote:

I spoke to @cjdb offline who told me there was a non-insignificant number of build failures when enabling this. However, this change can easily be disabled temporarily (while the code base migrates) by not defining `_LIBCPP_ABI_USE_WRAP_ITER_IN_STD_ARRAY` and `_LIBCPP_ABI_USE_WRAP_ITER_IN_STD_STRING_VIEW`.

Our ABI flags have that benefit that one can pick and choose what's opted into, so let's use this here. Hence, I think it is reasonable to move forward with the change, and vendors who envision breakage should simply disable these ABI macros until they are ready to transition.

CC @llvm/libcxx-vendors again

https://github.com/llvm/llvm-project/pull/74482