testsuite: Create a variant of uninit-pred-7_a.c [PR123377]

testsuite: Create a variant of uninit-pred-7_a.c [PR123377]

So it turns out the xfail uninit-pred-7_a.c didn't always happen
depending on the setting of logical-op-non-short-circuit.
So this creates a second copy of the testcase for the case
of `logical-op-non-short-circuit=0` without the xfail and then sets
`logical-op-non-short-circuit=1` for uninit-pred-7_a.c with still
the xfail.

Tested on x86_64-linux-gnu to make sure both pass and uninit-pred-7_a.c
xfails like it should. Also tested manually on powerpc64-linux-gnu to
see the bogus warning happen with logical-op-non-short-circuit=1.

	PR testsuite/123377
gcc/testsuite/ChangeLog:

	* gcc.dg/uninit-pred-7_a.c: Add
	`--param logical-op-non-short-circuit=1` to the options.
	* gcc.dg/uninit-pred-7_a_a.c: New test.

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