Use gcc by default for gyp untrusted ARM builds

src/untrusted/irt/irt.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.
 
 {
   'includes': [
     '../../../build/common.gypi',
   ],
   'variables': {
     'irt_sources': [
@@ skipping 101 matching lines @@
       },
       'sources': ['<@(irt_sources)', '<@(irt_browser)'],
       'include_dirs': ['../../../../ppapi'],
       'conditions': [
         ['target_arch == "x64" or target_arch == "ia32"', {
           'link_flags': [
              '-r',
              '-nostartfiles',
           ],
         }],
+        ['target_arch == "arm"', {
+          'compile_flags': [
+            '-mtp=soft'

[Derek Schuff, 2013/03/28 17:33:41]

seems odd that this is here for arm but the corresponding flags are not here for
x86. does this duplicate something in untrusted.gypi?

[Roland McGrath, 2013/03/28 17:37:54]

See newlib_tls_flags in untrusted.gypi; that uses it for all builds using
newlib, when it's only really needed or desireable for building components of
the IRT.

[Derek Schuff, 2013/03/28 17:49:31]

Got it. so this should only be here, and in whatever nlibs get linked into the
IRT (e.g. gio_lib, platform_lib, srpc_lib etc as listed in the dependencies
above)

[Sam Clegg, 2013/03/28 23:02:59]

Done.  Went for consistency with x86 which is to say that all newlib code built
by gyp has this flag now.

+          ],
+        }],
       ],
       'dependencies': [
         '<(DEPTH)/native_client/tools.gyp:prep_toolchain',
         '<(DEPTH)/native_client/src/untrusted/nacl/nacl.gyp:nacl_lib_newlib',
       ],
     },
   ],
 }