OSV-2020-827 Use-of-uninitialized-value in llvm_ks::isIntN

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22920 Crash type: Use-of-uninitialized-value Crash state: llvmks::isIntN X86AsmBackend::applyFixup llvmks::MCAssembler::layout...