Update GDB to properly handle DWARF v5 format.

Minimum updates to add proper handling for DWARF v5.

Test: built gdb, ran gdb on 4 variants of test program:
dwarf4 with dwo files; dwarf4 with .dwp file; dwarf5 with dwo
files; dwarf5 with dwp file.

Change-Id: Ibf752386adb14b7bf4e60d8ec79851f29bf17e11
5 files changed
tree: 17f674b4cb887856523e4c611da37358b2e01381
  1. gdb-8.3/
  2. gdb-9.2/