tree-optimization/122537 - do not elide maybe_zero condition for wrapping IV

tree-optimization/122537 - do not elide maybe_zero condition for wrapping IV

The following removes the optimization eliding the maybe_zero condition
from number_of_iterations_lt_to_ne when the IV can overflow since the
IV delta input is not accurately reflecting this.

	PR tree-optimization/122537
	* tree-ssa-loop-niter.cc (number_of_iterations_lt_to_ne): Register
	may_be_zero condition when the IV may overflow.

	* gcc.dg/torture/pr122537.c: New testcase.