Gcc: Suppress warnings in third_party

third_party/libxml/BUILD.gn

Index: third_party/libxml/BUILD.gn
diff --git a/third_party/libxml/BUILD.gn b/third_party/libxml/BUILD.gn
index 70b66ab53b30c3fc0a41d8516464b8bfb19ae259..2c755ae050122918edcb88549e2388d8a721b5d4 100644
--- a/third_party/libxml/BUILD.gn
+++ b/third_party/libxml/BUILD.gn
@@ -60,6 +60,12 @@ config("libxml_warnings") {
       # used with certain preprocessor defines set.
       "-Wno-unused-function",
     ]
+  } else if (is_linux) {
+    cflags = [
+      # gcc spits out a bunch of warnings about passing too many arguments to
+      # __xmlSimpleError.
+      "-Wno-format-extra-args",
+    ]
   }
 }