[Bug bootstrap/77917] undefined reference to '__aeabi_unwind_cpp_pr0' during ARM bootstrap

[tulipawn at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77917

--- Comment #3 from PeteVine <tulipawn at gmail dot com> ---
Unfortunately, even with `--with-build-config=bootstrap-lto` the result was
unchanged which makes the issue real after all?

Unsurprisingly, eliminating just the `-flto` flag (-flto=4 to be exact) led to
a successful bootstrap, as usual.