ICU in Chromium is compiled with exception disabled [1], but
U_NOEXCEPT is set to 'noexcept'  regardless of whether _HAS_EXCEPTION is set to 0 or (in source/common/unicode/platform.h ). [2].

Set U_NOEXCEPT to empty in our build files to avoid this issue.

[1] http://bugs.icu-project.org/trac/ticket/8343
[2] http://bugs.icu-project.org/trac/ticket/12406

BUG=575007
TEST=Build on Windows with MSVS 2015 succeeds.
R=thakis@chromium.org

Review URL: https://codereview.chromium.org/1816673002 .