Cleanup: make remaining gpu headers work in C++

source/blender/gpu/GPU_batch_presets.h

@@ -30,6 +30,10 @@
 #include "BLI_compiler_attrs.h"
 #include "BLI_sys_types.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* gpu_batch_presets.c */
 
 /* Replacement for gluSphere */
@@ -42,4 +46,8 @@ bool gpu_batch_presets_unregister(struct GPUBatch *preset_batch);
 void gpu_batch_presets_reset(void);
 void gpu_batch_presets_exit(void);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __GPU_BATCH_PRESETS_H__ */