[Bug tree-optimization/101830] [12 Regression] Incorrect error messages beginning with r12-2591 (backward jump threader)

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101830

--- Comment #5 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
If I commit the build patch, everyone who doesn't build with --disable-werror
will blame me for breaking bootstrap.

I thought perhaps the way safe_inc_pos was implemented might have made it
possible for the warning machinery to make this error, but I experimented with
changes and nothing helps.

Just to be clear:  The code is fine.  The warning is bogus.