CodeGen: Avoid dereferencing end() when unconstifying iterators

Rather than doing a funny dance that relies on dereferencing end() not
crashing, add some API to MachineInstrBundleIterator to get a non-const
version of the iterator.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278870 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed