while building icu.

The warning isn't very serious, and these functions are supposed to trap. Since
ICU's operator new/delete overrides are technically invalid, I filed
http://bugs.icu-project.org/trac/ticket/11122 with ICU for this.

BUG=82385

Review URL: https://codereview.chromium.org/508343002

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/icu52@291699 4ff67af0-8c30-449e-8e8b-ad334ec8d88c