ldist: Fix probability on loop exit

ldist: Fix probability on loop exit

While moving the phi part of removal of forwarder blocks,
I noticed that I was getting some failures due to "mismatch counts".
I worked around the issue by disabling the case where the forwarder
block would just get merged. I have now gone back and found
the problem is in ldist where it is removing the loop
by changing the exit to always exit but forgot to update
the edge to always probability. This fixes that and
also removes a few of the "mismatch counts".

Bootstrapped and tested on x86_64-linux-gnu.

gcc/ChangeLog:

	PR tree-optimization/103680
	* tree-loop-distribution.cc (destroy_loop): Set probability
	of the exit edge to be always.

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