gallium: add extern "C" guards

Added extern "C" __cplusplus guards on headers that did not have them.

Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>

src/gallium/auxiliary/util/u_transfer.h

@@ -10,6 +10,10 @@
 struct pipe_context;
 struct winsys_handle;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 boolean u_default_resource_get_handle(struct pipe_screen *screen,
                                       struct pipe_resource *resource,
                                       struct winsys_handle *handle);
@@ -95,4 +99,8 @@ void u_transfer_flush_region_vtbl( struct pipe_context *pipe,
 void u_transfer_unmap_vtbl( struct pipe_context *rm_ctx,
                             struct pipe_transfer *transfer );
 
+#ifdef __cplusplus
+} // extern "C" {
+#endif
+
 #endif

src/gallium/auxiliary/util/u_upload_mgr.h

@@ -38,6 +38,9 @@
 struct pipe_context;
 struct pipe_resource;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /**
  * Create the upload manager.
@@ -109,4 +112,8 @@ void u_upload_data(struct u_upload_mgr *upload,
                    unsigned *out_offset,
                    struct pipe_resource **outbuf);
 
+#ifdef __cplusplus
+} // extern "C" {
+#endif
+
 #endif