winegcc: Pass the C compiler name to winebuild.

tools/winegcc/winegcc.c

@@ -940,6 +940,7 @@ static void build(struct options* opts)
 
     /* run winebuild to generate the .spec.o file */
     spec_args = get_winebuild_args( opts );
+    strarray_add( spec_args, strmake( "--cc-cmd=%s", build_tool_name( opts, "gcc", CC )));
     spec_o_name = get_temp_file(output_name, ".spec.o");
     if (opts->force_pointer_size)
         strarray_add(spec_args, strmake("-m%u", 8 * opts->force_pointer_size ));