Adapt date test to be timezone independant.

R=yangguo@chromium.org
BUG=v8:1792
TEST=mjsunit/date

Review URL: http://codereview.chromium.org/8423004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9842 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/mjsunit/date.js

@@ -190,13 +190,8 @@ assertTrue(isNaN(d.getTime()));
 
 
 // Test creation with obscure date values.
-var timezoneOffset = new Date().getTimezoneOffset();
-d = new Date(1970, 0, 1 + 100000001, -24, -timezoneOffset);
-assertFalse(isNaN(d.getTime()));
-assertEquals(8640000000000000, d.getTime())
-d = new Date(1970, 0, 1 - 100000001, 24, -timezoneOffset);
-assertFalse(isNaN(d.getTime()));
-assertEquals(-8640000000000000, d.getTime())
+assertEquals(8640000000000000, Date.UTC(1970, 0, 1 + 100000001, -24));
+assertEquals(-8640000000000000, Date.UTC(1970, 0, 1 - 100000001, 24));
 
 
 // Parsing ES5 ISO-8601 dates.