OSV-2020-1349 Heap-buffer-overflow in mu::ParserBase::ParseCmdCodeBulk

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=23410 Crash type: Heap-buffer-overflow READ 8 Crash state: mu::ParserBase::ParseCmdCodeBulk mu::ParserBase::ParseString setevalfuzzer.cc...