Ignore conversions to NULL in gcc too.

hunspell.gyp

 # Copyright (c) 2009 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.
 
 {
   'targets': [
     {
       'target_name': 'hunspell',
       'type': 'static_library',
       'msvs_guid': 'D5E8DCB2-9C61-446F-8BEE-B18CA0E0936E',
@@ skipping 55 matching lines @@
       # TODO(jschuh): http://crbug.com/167187 size_t -> int
       'msvs_disabled_warnings': [ 4267 ],
       'conditions': [
         ['os_posix == 1 and OS != "mac"', {
           'cflags': [
             '-Wno-unused-value',
             '-Wno-unused-variable',
             '-Wno-write-strings',
           ],
         }],
+        ['gcc_version >= 48', {
+          'cflags': [
+              # affentry.hxx has NULL as default parameter for a FLAG in two
+              # places.
+              '-Wno-conversion-null',
+          ],
+        }],
         ['clang == 1', {
           'xcode_settings': {
             'WARNING_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',
             ],
           },
           'cflags': [
             '-Wno-empty-body',
             '-Wno-null-conversion',
           ],
         }],
       ],
     },
   ],
 }