Suppress new Clang warning: -Waddress-of-packed-member

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 588db2bca8e6df2ffbedbfc18d3531a1d1d46db4..79723f6cc76c041697955f5c7de91e2935e78aa5 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -1015,6 +1015,12 @@ config("default_warnings") {
         # TODO(thakis): https://crbug.com/617318
         "-Wno-nonportable-include-path",
       ]
+      if (llvm_force_head_revision) {
+        cflags += [
+          # TODO(hans): https://crbug.com/637306
+          "-Wno-address-of-packed-member",
+        ]
+      }
     }
   }
 }