[Bug tree-optimization/114040] wrong code with __builtin_sub_overflow_p() and _BitInt() at -O2 and above

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114040

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
` -fdisable-tree-evrp -fdisable-tree-vrp1` also fixes it.

EVRP and VRP1 changes:
  _3 = IMAGPART_EXPR <_8>;
  _4 = (_Bool) _3;
  _5 = (unsigned _BitInt(8671)) _4;

into
  _7 = .SUB_OVERFLOW (_2, 0);
  _3 = IMAGPART_EXPR <_7>;
  _4 = (unsigned _BitInt(8671)) _3;

Which looks fine.

Then bitlower looks to go wrong.