Fix ICU time zone support on iOS

tzfile.h isn't available on iOS, and the time zone is not set the way it is on OS X, so don't define U_TIMEZONE. Also disables a code path in the non-U_TIMEZONE implmentation that makes a correction that is incorrect on iOS.

Fixes the following upstream ICU bugs:
  http://bugs.icu-project.org/trac/ticket/9051
  http://bugs.icu-project.org/trac/ticket/8661

BUG=None
TEST=None (will be covered by base unit tests once they come online upstream)

Review URL: https://chromiumcodereview.appspot.com/10692124

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/icu46@146527 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
4 files changed