ifcvt: Only allow scalar integral modes for noce_try_cond_zero_arith [PR123276]

ifcvt: Only allow scalar integral modes for noce_try_cond_zero_arith [PR123276]

This is the simple fix for PR 123276 where this code can only handle scalar
integral modes. We could in theory handle scalar floating point modes here
too but it is not worth the trouble.

Pushed as obvious after bootstrap/test on x86_64-linux-gnu.

	PR rtl-optimization/123276
gcc/ChangeLog:

	* ifcvt.cc (noce_try_cond_zero_arith): Reject non-scalar integral modes.

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