Debug Info: Move the sorting and uniqueing of pieces from emitLocPieces()
into buildLocationList(). By keeping the list of Values sorted,
DebugLocEntry::Merge can also merge multi-piece entries.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215384 91177308-0d34-0410-b5e6-96231b3b80d8
Debug info: Further simplify the implementation of buildLocationList by
getting rid of the redundant DIVariable in the OpenRanges pair.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215385 91177308-0d34-0410-b5e6-96231b3b80d8
Debug info: Modify DebugLocEntry::addValue to take multiple values so it
only has to sort/unique values once per batch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215386 91177308-0d34-0410-b5e6-96231b3b80d8
Debug info: Remove an obsolete constructor from DebugLocEntry.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215387 91177308-0d34-0410-b5e6-96231b3b80d8