[OperandBundles] Have GlobalsModRef play nice with operand bundles

A call site's use of a Value might not correspond to an argument
operand but to a bundle operand.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256329 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed