[NaCl SDK] Add arm gcc toolchain support to the SDK

native_client_sdk/src/libraries/gtest/library.dsc

 {
   # TODO(binji): pnacl fails with error:
   # In file included from gtest.cc:133:
   # pepper_23/include/gtest/internal/src/gtest-internal-inl.h:213:8:
   #   error: private field 'pretty_' is not used [-Werror,-Wunused-private-field]
   #
   # We can fix this by passing -Wno-unused-private-field to clang, but gcc
   # doesn't support this flag so we'll have to support splitting CXXFLAGS based
   # on TOOL first.
-  'TOOLS': ['newlib', 'glibc', 'win', 'linux'],
+  'TOOLS': ['newlib:x86', 'newlib:x64', 'glibc', 'win', 'linux'],
   'SEARCH': [
     '.',
     '../../../../testing/gtest/include/gtest',
     '../../../../testing/gtest/include/gtest/internal',
     '../../../../testing/gtest/src',
   ],
   'TARGETS': [
     {
       'NAME' : 'gtest',
       'TYPE' : 'lib',
@@ skipping 57 matching lines @@
       # spot.
       'FILES': [
         'gtest-internal-inl.h',
       ],
       'DEST': 'include/gtest/internal/src',
     },
   ],
   'DEST': 'testlibs',
   'NAME': 'gtest',
 }