glsl: Include main/core.h.

Make glsl include only main/core.h from core mesa.
diff --git a/src/glsl/link_functions.cpp b/src/glsl/link_functions.cpp
index dfda05f..6374573 100644
--- a/src/glsl/link_functions.cpp
+++ b/src/glsl/link_functions.cpp
@@ -29,7 +29,7 @@
 #include <talloc.h>
 }
 
-#include "main/mtypes.h"
+#include "main/core.h"
 #include "glsl_symbol_table.h"
 #include "glsl_parser_extras.h"
 #include "ir.h"