[DWARFLinker][DWARFv5] Support debug_loclists.

This patch adds support of DWARFv5 .debug_loclists table.
As DWARFLinker resolves relocations, it is able to always
use DW_FORM_addr instead of DW_FORM_addrx. DW_FORM_addrx
helps to minimize number of relocations, it is also used for
split DWARF. Both of these cases are not relevant for the
DWARFLinker. Thus, this patch converts all DW_FORM_addrx
forms into the DW_FORM_addr. And, as the result, it converts
location lists of DW_FORM_loclistx form into the DW_FORM_sec_offset.
For the --update case all DW_FORM_addrx, DW_FORM_loclistx
are preserved as is.

Depends On D145499

Differential Revision: https://reviews.llvm.org/D145680