[Bug rtl-optimization/80197] pgo dramatically pessimizes scimark2 MonteCarlo benchmark

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80197

--- Comment #9 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
The original idea of tracing was that we can pro-actively duplicate tails and
rely on crossjumping to merge the paths back if they did not trigger context
sensitive optimizations.  Nowdays crossjumping much weaker than it used to be
because it does not handle well RTL genertated from SSA and we do not do any
gimple level tail merging after tracer which we probably should.