[DwarfDebug] Don't merge DebugLocEntries if their pieces overlap

Summary:
Later in DWARF emission we check that DebugLocEntries have
non-overlapping pieces, so we should create any such entries
by merging here.

Fixes PR26163.

Reviewers: aprantl
Differential Revision: http://reviews.llvm.org/D16249

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257979 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed