In case of calling 'toLocaleString', 'toLocaleTimeString' and
'toLocaleDateString' functions of 'Date' with empty 'locales' and
'options', DateTimeFormat is cached inside 'defaultObjects'.
If we change the timezone the cache is not invalidated.

BUG=v8:5022
TEST=cctest:DateCacheVersion. See the bug
CQ_INCLUDE_TRYBOTS=tryserver.v8:v8_linux_noi18n_rel_ng

Review-Url: https://codereview.chromium.org/1985423003
Cr-Commit-Position: refs/heads/master@{#36420}