Un-nest configs in GN files.

third_party/hunspell/BUILD.gn

Index: third_party/hunspell/BUILD.gn
diff --git a/third_party/hunspell/BUILD.gn b/third_party/hunspell/BUILD.gn
index 9e9f249e5b31b59ee0ca12a8768d4e9db942da67..84f0ae76700c4e38a71081fa5e2eae6edc9cb8eb 100644
--- a/third_party/hunspell/BUILD.gn
+++ b/third_party/hunspell/BUILD.gn
@@ -10,6 +10,12 @@ config("hunspell_config") {
   ]
 }
 
+config("hunspell_warnings") {
+  if (is_clang) {
+    cflags = [ "-Wno-unused-private-field" ]
+  }
+}
+
 source_set("hunspell") {
   sources = [
     "google/bdict.cc",
@@ -51,12 +57,6 @@ source_set("hunspell") {
     "src/parsers/textparser.hxx",
   ]
 
-  config("hunspell_warnings") {
-    if (is_clang) {
-      cflags = [ "-Wno-unused-private-field" ]
-    }
-  }
-
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [
     "//build/config/compiler:no_chromium_code",