[Bug gcov-profile/118442] -fprofile-generate wrongly adds instrumentation after musttail call

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118442

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #5)
> That comes from flow_call_edges_add, see gimple_flow_call_edges_add in
> tree-cfg.cc

Reading the comments in gimple_flow_call_edges_add is interesting because it
looks like it was copied directly from the rtl version and we didn't insert the
fake edge for tails calls back when the profiling was on the RTL.