[DWARFDebugLoclists] Add support for other DW_LLE encodings

Summary:
lldb's loclists parser has support for DW_LLE_start_end(x) encodings. To
avoid regressing when switching the implementation to llvm's, I add
parsing support for all previously unsupported location list encodings.

Reviewers: dblaikie, JDevlieghere, aprantl, SouraVX

Subscribers: hiraditya, probinson, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70949