Tweaks to generate XP-compatible .exes

BUG=407517
LOG=y
R=machenbach@chromium.org

Review URL: https://codereview.chromium.org/504793004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23436 ce2b1a6d-e550-0410-aec6-3dcde31c8c00