[MachO] Add out-of-bounds check to MachOObjectFile.cpp

This is a followup to rL333496.

Differential Revision: https://reviews.llvm.org/D47544

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333929 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed