configure: use standard check for attribure alias

Currently we have two macros - HAVE_ALIAS and GLX_ALIAS_UNSUPPORTED.
To make it even better former of which is explicitly cleared in some
cases while not in others.

Clear all that up by using a single macro properly set during configure.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>

diff --git a/configure.ac b/configure.ac
index beacd11..e6b4d8c 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -239,6 +239,7 @@ AX_GCC_FUNC_ATTRIBUTE([unused])
 AX_GCC_FUNC_ATTRIBUTE([visibility])
 AX_GCC_FUNC_ATTRIBUTE([warn_unused_result])
 AX_GCC_FUNC_ATTRIBUTE([weak])
+AX_GCC_FUNC_ATTRIBUTE([alias])
 
 AM_CONDITIONAL([GEN_ASM_OFFSETS], test "x$GEN_ASM_OFFSETS" = xyes)