phi-opt: Improve factor heurstic with constants and conversions from bool [PR116890]

Take:
```
  if (t_3(D) != 0)
    goto <bb 3>;
  else
    goto <bb 4>;

  <bb 3>
  _8 = c_4(D) != 0;
  _9 = (int) _8;

  <bb 4>
  # e_2 = PHI <_9(3), 0(2)>
```

We should factor out the conversion here as that will allow a simplfication to
`(t_3 != 0) & (c_4 != 0)`. Unlike most other types; `a ? b : CST` will simplify
for boolean result type to either `a | b` or `a & b` so allowing this conversion
for all operations will be always profitable.

Bootstrapped and tested on x86_64-linux-gnu with no regressions.

Note on the phi-opt-7.c testcase change, we are now able to optimize this
and remove the if due to the factoring out now so this is an improvement.

	PR tree-optimization/116890

gcc/ChangeLog:

	* tree-ssa-phiopt.cc (factor_out_conditional_operation): Conversions
	from bool is also should be considered as wanting to happen.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/phi-opt-7.c: Update testcase for no ifs left.
	* gcc.dg/tree-ssa/phi-opt-42.c: New test.
	* gcc.dg/tree-ssa/phi-opt-43.c: New test.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>