OSV-2020-853 Use-of-uninitialized-value in llvm_ks::MCAssembler::computeFragmentSize

OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=22482 Crash type: Use-of-uninitialized-value Crash state: llvmks::MCAssembler::computeFragmentSize llvmks::MCAsmLayout::layoutFragment llvmks::MCAsmLayout::ensureValid...