[Bug bootstrap/93398] PGO bootstrap is not reproducible

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93398

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #2)
> Couldn't e.g. address space randomization of the instrumented binaries
> (compiler itself) matter?

I bet some hash-tables could end up with different access patterns because of
that.  Also we use "randomness" (for temporary filenames, etc.) which also
can result in some counter differences in routines processing those.

But yes, individual inspection of the differences might uncover real issues
(but for a start I'd disable address-space randomization).