Merge "gn: Disable new GCC redundant move warning"

gn/standalone/BUILD.gn

diff --git a/gn/standalone/BUILD.gn b/gn/standalone/BUILD.gn
index 9928a72..f11bb5f 100644
--- a/gn/standalone/BUILD.gn
+++ b/gn/standalone/BUILD.gn
@@ -54,6 +54,11 @@
       "-Wno-unknown-sanitizers",
     ]
   }
+
+  if (!is_clang) {
+    # Use return std::move(...) for compatibility with old compilers.
+    cflags += [ "-Wno-redundant-move" ]
+  }
 }
 
 config("no_exceptions") {