Un-nest configs in GN files.

third_party/hunspell/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 config("hunspell_config") {
   defines = [
     "HUNSPELL_STATIC",
     "HUNSPELL_CHROME_CLIENT",
     "USE_HUNSPELL",
   ]
 }
 
+config("hunspell_warnings") {
+  if (is_clang) {
+    cflags = [ "-Wno-unused-private-field" ]
+  }
+}
+
 source_set("hunspell") {
   sources = [
     "google/bdict.cc",
     "google/bdict.h",
     "google/bdict_reader.cc",
     "google/bdict_reader.h",
     "google/bdict_writer.cc",
     "google/bdict_writer.h",
     "src/hunspell/affentry.cxx",
     "src/hunspell/affentry.hxx",
@@ skipping 21 matching lines @@
     "src/hunspell/replist.cxx",
     "src/hunspell/replist.hxx",
     "src/hunspell/suggestmgr.cxx",
     "src/hunspell/suggestmgr.hxx",
     "src/hunspell/utf_info.hxx",
     "src/hunspell/w_char.hxx",
     "src/parsers/textparser.cxx",
     "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",
     ":hunspell_warnings",
   ]
   public_configs = [ ":hunspell_config" ]
 
   defines = [ "OPENOFFICEORG" ]
 
   deps = [
@@ skipping 30 matching lines @@
     cflags += [
       # affentry.cxx has one `while ((p = nextchar(p)));` parsing loop.
       "-Wno-empty-body",
 
       # affentry.hxx has NULL as default parameter for a FLAG in two
       # places.
       "-Wno-null-conversion",
     ]
   }
 }