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
--- a/configure.ac
+++ b/configure.ac
@@ -239,6 +239,7 @@
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)