allegro5: fix FTBFS with newer mesa

srcpkgs/allegro4/template

@@ -1,4 +1,4 @@
-# Template file for 'allegro4'.
+# Template file for 'allegro4'
 pkgname=allegro4
 version=4.4.2
 revision=6

srcpkgs/allegro5/patches/fix_building_with_newer_mesa.patch

@@ -0,0 +1,29 @@
+--- include/allegro5/allegro_opengl.h
++++ include/allegro5/allegro_opengl.h
+@@ -103,10 +103,14 @@
+ 
+ /* HACK: Prevent both Mesa and SGI's broken headers from screwing us */
+ #define __glext_h_
++#define __gl_glext_h_
+ #define __glxext_h_
++#define __glx_glxext_h_
+ #include <GL/gl.h>
+ #undef  __glext_h_
++#undef  __gl_glext_h_
+ #undef  __glxext_h_
++#undef  __glx_glxext_h_
+ 
+ #endif /* ALLEGRO_MACOSX */
+
+--- include/allegro5/opengl/GLext/glx_ext_defs.h
++++ include/allegro5/opengl/GLext/glx_ext_defs.h
+@@ -1,7 +1,9 @@
+ /* HACK: Prevent both Mesa and SGI's broken headers from screwing us */
+ #define __glxext_h_
++#define __glx_glxext_h_
+ #include <GL/glx.h>
+ #undef __glxext_h_
++#undef __glx_glxext_h_
+ 
+ #ifndef GLX_VERSION_1_3
+ #define _ALLEGRO_GLX_VERSION_1_3

srcpkgs/allegro5/template

@@ -1,4 +1,4 @@
-# Template file for 'allegro5'.
+# Template file for 'allegro5'
 pkgname=allegro5
 version=5.2.3.0
 revision=1