[libc++] Skip logic for detecting C11 features when using_if_exists is supported
authorLouis Dionne <ldionne.2@gmail.com>
Tue, 17 Aug 2021 15:23:48 +0000 (11:23 -0400)
committerLouis Dionne <ldionne.2@gmail.com>
Wed, 18 Aug 2021 15:53:34 +0000 (11:53 -0400)
commitebc01bbc7a6758743e6383af34619ef1423afa15
tree5b6204f4694d7da584e3dc725b7cd2169ea050f1
parentec574f5da463d303a3771597c233e52d2429db67
[libc++] Skip logic for detecting C11 features when using_if_exists is supported

In the future, we'll want to rely exclusively on using_if_exists for this
job, but for now, only rely on it when the compiler supports that attribute.
That removes the possibility for getting the logic wrong.

Differential Revision: https://reviews.llvm.org/D108297
libcxx/include/__config
libcxx/include/ctime