tree fb2c652b8fa030863a03f78959ad7753a5d4fbc4
parent f95311664d6c210d05fe66bf6a1d919c67ab6699
author Colin Finck <colin@reactos.org> 1613487784 -0500
committer Copybara-Service <copybara-worker@google.com> 1613725624 -0800

[libc++] Build thread_win32.cpp only if LIBCXX_HAS_PTHREAD_API is not set

This allows building libc++ against winpthreads from mingw-w64 to support
operating systems older than Windows 7. The remaining libc++ code already
supports `WIN32` with `LIBCXX_HAS_PTHREAD_API`.

Note that there is also the older "pthreads-win32". However, that support
library implements `pthread_t` as a struct, which violates the libc++
assumption that `pthread_t` is always a scalar and can be compared,
ordered, and set to zero.

Differential Revision: https://reviews.llvm.org/D96339

GitOrigin-RevId: 0f5020af7f347f029b5687f7a6d3b72174995d59