Reapply: DebugInfo: Add missing test coverage for DW_OP_convert in loclists

Originally committed in: 5327b917
      and follow on fix: 4f281f04

            Reverted in: 191a9a78
	            and: f75301d1

Reverted because it wasn't portable between the targets it was running
on. Using %llc_dwarf ensures the target triple is always elfine and thus
DWARF compatible.