OSV-2020-1455 Segv on unknown address in clang::Parser::ParseObjCInterfaceDeclList

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=19088 Crash type: Segv on unknown address Crash state: clang::Parser::ParseObjCInterfaceDeclList clang::Parser::ParseObjCAtInterfaceDeclaration clang::Parser::ParseObjCAtDirectives...