[Bug libstdc++/85768] [9 Regression] FreeBSD bootstrap fails due to undefined reference to 'backtrace'

[fdumont at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85768

--- Comment #4 from François Dumont <fdumont at gcc dot gnu.org> ---
Created attachment 44187
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44187&action=edit
Remove backtrace usage during bootstrap.

I wonder if this patch could fix the bootstrap ? I try to avoid the usage of
backtrace during bootstrap. The problem will then be limited to usage of debug
mode in users code.

I still plan to use libbacktrace but it will take me some time to find out how.