[Bug rtl-optimization/68435] [6 Regression] Missed if-conversion optimization

[ysrumyan at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68435

--- Comment #2 from Yuri Rumyantsev <ysrumyan at gmail dot com> ---
I will post 2 rtl dumps for ce1 phase produced with -O2 -m32 options on ix86.
You can see that file t21.c.203r.ce1 produced by 20110927 compiler contains
3 possible IF blocks searched.
1 IF blocks converted.
2 true changes made.
but file t21.c.209r.ce1 produced by 20151119 compiler does not
1 possible IF blocks searched.
0 IF blocks converted.
0 true changes made.