OSV-2020-797 Use-of-uninitialized-value in MipsAsmParser::isPicAndNotNxxAbi

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22778 Crash type: Use-of-uninitialized-value Crash state: MipsAsmParser::isPicAndNotNxxAbi MipsAsmParser::processInstruction MipsAsmParser::MatchAndEmitInstruction...