clang: Add -Wno-empty-body to libxml and hunspell flags

third_party/libxml/libxml.gyp

 # Copyright (c) 2012 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.
 
 {
   'variables': {
     'conditions': [
       # Define an "os_include" variable that points at the OS-specific generated
       # headers.  These were generated by running the configure script offline.
       ['os_posix == 1 and OS != "mac"', {
@@ skipping 179 matching lines @@
             ['OS=="win"', {
               'product_name': 'libxml2',
             }, {  # else: OS!="win"
               'product_name': 'xml2',
             }],
             ['clang == 1', {
               'xcode_settings': {
                 'WARNING_CFLAGS': [
                   # libxml passes `const unsigned char*` through `const char*`.
                   '-Wno-pointer-sign',
+                  # pattern.c and uri.c both have an intentional
+                  # `for (...);` / `while(...);` loop. I submitted a patch to
+                  # move the `'` to its own line, but until that's landed
+                  # suppress the warning:
+                  '-Wno-empty-body',
                 ],
               },
               'cflags': [
                 '-Wno-pointer-sign',
+                '-Wno-empty-body',
               ],
             }],
           ],
         }],
       ],
     },
   ],
 }