OSV-2022-1142 Heap-buffer-overflow in onigenc_unicode_mbc_case_fold

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=53030 Crash type: Heap-buffer-overflow READ 1 Crash state: onigencunicodembccasefold mbccasefold stringcmpic...