This patch reverts patch "DWARFv5 default: Switch bolt tests to use
DWARFv4 since Bolt doesn't support v5 yet" and places the -gdwarf-4 flag
to the global cflags config file.
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D118283
Summary:
While printing debug info for instructions, we should use line tables
from the corresponding DWARF CU which could be different from the
containing function CU in case of inlined instructions.
(cherry picked from FBD28908324)
