testsuite: Add new variant of pr42196-3.c

testsuite: Add new variant of pr42196-3.c

While working on complex lowering, I noticed that the
testcase pr42196-3.c had some interesting code in it
and most likely a copy and pasto. Since this testcase
was added back in 2009, I rather add a new testcase
rather than changing the old one.
The testcase was doing:
```
  if (b)
    {
      f1 = __real__ u.cf;
      f1 = __imag__ u.cf;
    }
  else
    {
      f1 = __real__ u.ci;
      f1 = __imag__ u.ci;
    }

  r = bar (f1, f2);
```
I suspect the second f1 in both sides of the conditional
were supposed to be f2. So the new testcase does that.

Tested on x86_64-linux-gnu and pushed as obvious.

	PR tree-optimization/42196

gcc/testsuite/ChangeLog:

	* gcc.c-torture/compile/pr42196-4.c: New test.

Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>