Switch to thumb mode for runtime system on Android.

Review URL: http://codereview.chromium.org/57054

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1652 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

SConstruct

@@ -98,7 +98,7 @@ LIBRARY_FLAGS = {
       'CCFLAGS':      ['-O3', '-fomit-frame-pointer', '-fdata-sections',
                        '-ffunction-sections'],
       'os:android': {
-        'CCFLAGS':      ['-Os'],
+        'CCFLAGS':    ['-mthumb'],
         'CPPDEFINES': ['SK_RELEASE', 'NDEBUG']
       }
     },