32-bit linux: Force 16-byte stack alignment.

build/standalone.gypi

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 445 matching lines @@
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags+': [
                   '-Wno-format-pedantic',
                  ],
               }],
            ],
           }],
         ],
       }],
+      ['clang==1 and target_arch=="ia32"', {
+        'cflags': ['-mstack-alignment=16', '-mstackrealign'],
+      }],
       ['fastbuild!=0', {
         'conditions': [
           ['OS=="win" and fastbuild==1', {
             'msvs_settings': {
               'VCLinkerTool': {
                 # This tells the linker to generate .pdbs, so that
                 # we can get meaningful stack traces.
                 'GenerateDebugInformation': 'true',
               },
               'VCCLCompilerTool': {
@@ skipping 963 matching lines @@
               '-fsanitize=cfi-vcall',
               '-fsanitize=cfi-derived-cast',
               '-fsanitize=cfi-unrelated-cast',
             ],
           }],
         ],
       },
     }],
   ],
 }