tests: add comment about GCC bug

tests/test_platform.c

@@ -63,7 +63,12 @@ const char* test_platform__global_h()
 
 const char* test_platform__compiler()
 {
-    /* Check that initialization with { 0 } works as expected */
+    /* Check that initialization with { 0 } works as expected
+     *
+     * Depending on your version, GCC can incorrectly reports the warning
+     * "missing braces around initializer [-Wmissing-braces]"
+     * See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119
+     */
     {
         const gmio_transfer_t trsf_null_bracket0 = { 0 };
         gmio_transfer_t trsf_null_memset0;