Configuring with -Werror

[Jerome Leclanche]

Configuring with -Werror used to work a while back for me; now that
-Wno-unused-result has been fixed I gave it another try and got this:

configure: libxrandr 32-bit development files not found, XRandr won't
be supported.
configure: WARNING: Old Mesa headers detected. Consider upgrading your
Mesa libraries.
OpenGL and Direct3D won't be supported.
configure: WARNING: No sound system was found. Windows applications
will be silent.

After a quick investigation, turns out many configure checks produce
warnings; patch below hacks around it, but I've never dealt with
configure before and apparently fixes need to go in configure.ac --
anyone wants to give it a proper shot?

Jerome L.

diff --git a/configure b/configure
index 05a9317..ae29fe4 100755
--- a/configure
++

J. Leclanche / Adys+ b/configure
@@ -8430,7 +8430,7 @@ int
 main ()
 {
 static typeof(XRRSetScreenConfigAndRate) * func;
-  ;
+  if(func);
   return 0;
 }
 _ACEOF
@@ -8685,7 +8685,7 @@ int
 main ()
 {
 GLenum test = GL_UNSIGNED_SHORT_5_6_5;
-  ;
+  if(test);
   return 0;
 }
 _ACEOF
@@ -10517,8 +10517,8 @@ if test
"x$ac_cv_lib_asound_snd_pcm_hw_params_get_access" = x""yes; then :
 int
 main ()
 {
-int ret = snd_pcm_hw_params_get_access(NULL, NULL)
-  ;
+int ret = snd_pcm_hw_params_get_access(NULL, NULL);
+  if(ret);
   return 0;
 }
 _ACEOF