CP PR 2070 fix int32 overflow

https://github.com/unicode-org/icu/pull/2070
https://unicode-org.atlassian.net/browse/ICU-22005

Bug: chromium:1316946
Change-Id: I6cd7d687a55b6cc157b1afa52365908be2992fa6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/deps/icu/+/3614280
Reviewed-by: Jungshik Shin <jshin@chromium.org>
4 files changed