[X86] Check return value of readSIB in disassembler so errors propagate. In particular this makes a too short instruction with a missing SIB byte fail.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204305 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed