Align host and target architectures when building v8_shell.

This is a fix after r8356. Otherwise, shell can't be built
on a 64-bit host.

R=ager@chromium.org

Review URL: http://codereview.chromium.org/7328016

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8581 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

tools/gyp/v8.gyp

@@ -286,6 +286,12 @@
           'conditions': [
             ['component=="shared_library"', {
               'conditions': [
+                # The ARM assembler assumes the host is 32 bits, so force building
+                # 32-bit host tools.
+                ['v8_target_arch=="arm" and host_arch=="x64" and _toolset=="host"', {
+                  'cflags': ['-m32'],
+                  'ldflags': ['-m32'],
+                }],
                 ['OS=="win"', {
                   'defines': [
                     'BUILDING_V8_SHARED',
@@ -971,6 +977,12 @@
               # This could be gotten by not setting chromium_code, if that's OK.
               'defines': ['_CRT_SECURE_NO_WARNINGS'],
             }],
+            # The ARM assembler assumes the host is 32 bits, so force building
+            # 32-bit host tools.
+            ['v8_target_arch=="arm" and host_arch=="x64" and _toolset=="host"', {
+              'cflags': ['-m32'],
+              'ldflags': ['-m32'],
+            }],
             ['v8_compress_startup_data=="bz2"', {
               'libraries': [
                 '-lbz2',