[LiveDebugValues] Insert entry values after bundles

Summary:
Change LiveDebugValues so that it inserts entry values after the bundle
which contains the clobbering instruction. Previously it would insert
the debug value after the bundle head using insertAfter(), breaking the
bundle.

Reviewers: djtodoro, NikolaPrica, aprantl, vsk

Reviewed By: vsk

Subscribers: hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D66888

llvm-svn: 370448