[Bug target/66874] RFE: x86_64_fallback_frame_state more robust

[schwab--- via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66874

--- Comment #5 from Andreas Schwab <sch...@linux-m68k.org> ---
If the unwinder crashes you have either incorrect unwind info or a corrupted
stack.  Neither should be papered over.