RangeDataVector: Support custom sorting for D63540

As suggested by @labath extended RangeDataVector so that user can provide
custom sorting of the Entry's `data' field for D63540.
        https://reviews.llvm.org/D63540

RangeData functions were used just by RangeDataVector (=after I removed them
LLDB still builds fine) which no longer uses them so I removed them.

Differential revision: https://reviews.llvm.org/D72460