gallium/aux: Add needed extern "C" wrappers

Reviewed-by: Brian Paul <brianp@vmware.com>

src/gallium/auxiliary/postprocess/postprocess.h

@@ -30,6 +30,10 @@
 
 #include "pipe/p_state.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 struct cso_context;
 
 struct pp_queue_t;              /* Forward definition */
@@ -85,4 +89,9 @@ void pp_celshade_free(struct pp_queue_t *, unsigned int);
 void pp_nocolor_free(struct pp_queue_t *, unsigned int);
 void pp_jimenezmlaa_free(struct pp_queue_t *, unsigned int);
 
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif

src/gallium/auxiliary/util/u_tests.h

@@ -30,8 +30,16 @@
 
 #include "pipe/p_compiler.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 struct pipe_screen;
 
 void util_run_tests(struct pipe_screen *screen);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif