configure: make the check for stdatomic.h stricter
authorJames Almer <jamrial@gmail.com>
Wed, 28 Dec 2016 00:54:55 +0000 (21:54 -0300)
committerJames Almer <jamrial@gmail.com>
Fri, 30 Dec 2016 03:01:38 +0000 (00:01 -0300)
commit6993bb4eb6c358c390f674a10f8a8ca69d9ee0fe
tree9f8b51b6acdd83c63ecaf3cd55b08af550d782d2
parentffc3337e0b84ba83fb78382e89a24bb92733bb0d
configure: make the check for stdatomic.h stricter

Old ICC verions don't advertise having a full C11 implementation but
may nonetheless include a feature-incomplete stdatomic.h header.

Fixes ticket #6049

Signed-off-by: James Almer <jamrial@gmail.com>
configure