Make clang the default Android compiler.

gyp/lua.gyp

 #
 # Copyright 2013 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 
 {
   'targets': [
     {
@@ skipping 52 matching lines @@
         ['skia_os != "win"',
          {
             'defines': [
               'LUA_USE_POSIX',  # Fix warning re dangerous tmpnam.
             ],
           }
         ],
         [ 'skia_clang_build == 1', {
           'cflags':[
             '-Wno-error',
+            '-Wno-parentheses-equality',
+            '-Wno-pointer-bool-conversion',
           ],
         }],
       ],
     },
   ],
 }