Add more historic DWARF vendor extensions

The maintainer of libdwarf kindly provided this patch with a bunch of
historic DWARF extensions that are missing from Dwarf.def. This list
is helpful to avoid potential conflicts in the user-defined vendor
extension space in the future.

Patch by David Anderson!

[Relanded with an updated test.]

Differential Revision: https://reviews.llvm.org/D97242