Fix uregex_open_fuzzer: hardcoded flags and unaligned memory access#3919

OwenSanzas wants to merge 2 commits intounicode-org:mainunicode-org/icu:mainfrom

OwenSanzas:fix-uregex-open-fuzzer-flagsOwenSanzas/icu:fix-uregex-open-fuzzer-flagsCopy head branch name to clipboard