Generating unwind information is entangled with supporting exceptions,
even when AsmPrinter explicitly recognizes that the unwind tables are
being generated only as debug information.
Add SupportsDebugOnlyCFI as a workaround for targets which do not have
EH support but which do support unwind information for debugging. This
new option only has an effect when the None EH model is specified. The
option requests that .debug_frame be generated when debug info is
Enable the new option for AMDGPU to prepare for future patches which add
complete CFI support, and to enable testing.