range-op: Implement floating point division fold_range [PR107569]

Here is the floating point division fold_range implementation,
as I wrote in the last mail, we could outline some of the common parts
into static methods with descriptive names and share them between
foperator_div and foperator_mult.

Regressions are
+FAIL: gcc.dg/pr95115.c execution test
+FAIL: libphobos.phobos/std/math/hardware.d execution test
+FAIL: libphobos.phobos_shared/std/math/hardware.d execution test
The first test is we have:
  # RANGE [frange] double [] +-NAN
  _3 =  Inf /  Inf;
  if (_3 ord _3)
    goto <bb 3>; [INV]
  else
    goto <bb 4>; [INV]

  <bb 3> :
  abort ();

  <bb 4> :
before evrp, the range is correct, Inf / Inf is known NAN of unknown
sign.  evrp correctly folds _3 ord _3 into false and the
  _3 =  Inf /  Inf;
remains in the IL, but then comes dse1 and removes it as dead
statement.  So, I think yet another example of the PR107608 problems
where DCE? removes dead statements which raise floating point exceptions.
And -fno-delete-dead-exceptions doesn't help.

2022-11-12  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/107569
	* range-op-float.cc (foperator_div): New class.
	(floating_op_table::floating_op_table): Use foperator_div
	for RDIV_EXPR.