[Bug tree-optimization/64295] [5 Regression] ICE: SIGSEGV (infinite recursion) with -frounding-math -funsafe-math-optimizations

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64295

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Ok, so we're folding g / 3 -> g * (1 / 3) and then applyign the same transform
to 1 / 3 (because that's not constant folded with -frounding-math).  I believe
the option combination is a red herring, but ...

The original fold-const.c code only transformed this if 1 / 3 constant folded
but I used fold_binary in the pattern (because const_binop wasn't available
at the point of writing it).

Testing a patch.