Casting NaN to int is unpredictable, on different architectures it produces different int value.

TEST=test262/S15.4.4.10_A2.1_T2, test262/S15.4.4.10_A2.2_T2

BUG=

Review URL: https://codereview.chromium.org/14812014

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14621 ce2b1a6d-e550-0410-aec6-3dcde31c8c00