[PATCH] D25741: [libc++] Add configuration define for off_t functions

[Marshall Clow via cfe-commits]

mclow.lists added a comment.

I like this; I would like to see no mentions of `_WIN32` outside of `<__config>`.
That being said, we usually write things in the negative in libc++.

So the flag would be `_LIBCPP_HAS_NO_OFF_T_FUNCTIONS`, and the tests would be `#ifdef _LIBCPP_HAS_NO_OFF_T_FUNCTIONS`


https://reviews.llvm.org/D25741