Add SSE2 compilation mode ofr Linux ia32.

tools/gyp/configurations_make.gypi

 # Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 {
   'variables': {
     'dart_debug_optimization_level%': '2',
   },
   'target_defaults': {
     'configurations': {
@@ skipping 12 matching lines @@
           #'-ansi',
           '-fno-rtti',
           '-fno-exceptions',
           # '-fvisibility=hidden',
           # '-fvisibility-inlines-hidden',
         ],
       },
 
       'Dart_Linux_ia32_Base': {
         'abstract': 1,
-        'cflags': [ '-m32', '-msse2' ],
+        'cflags': [ '-m32', '-msse2', '-mfpmath=sse' ],
         'ldflags': [ '-m32', ],
       },
 
       'Dart_Linux_x64_Base': {
         'abstract': 1,
         'cflags': [ '-m64', '-msse2' ],
         'ldflags': [ '-m64', ],
       },
 
       'Dart_Linux_simarm_Base': {
@@ skipping 103 matching lines @@
           # The sampling profiler uses the frame pointer to walk the stack.
           '-fno-omit-frame-pointer',
           # Clang on Linux will still omit frame pointers from leaf functions
           # unless told otherwise:
           # '-mno-omit-leaf-frame-pointer',
         ],
       },
     },
   },
 }