[ObjCARC] Handle ARCInstKind::ClaimRV in OptimizeIndividualCalls.

When support for objc_unsafeClaimAutoreleasedReturnValue has been added to the
ARC optimizer in r258970, one case was missed which would lead the optimizer
to execute an llvm_unreachable. In this case, just handle ClaimRV in the same
way we handle RetainRV.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261134 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed