tree-optimization: Fix ICE in tree-parloops.cc reduction_phi() [PR118205]

Prior to r15-6001, reduction_phi() could be called with the PHI parameter
not actually being a gphi*. The search through reduction_list would fail and
return NULL. r15-6001 added a requirement that PHI actually be a gphi*, but
did not add a check for this. The PR shows an example where the check is
needed; fix by explicitly returning NULL in this case.

gcc/ChangeLog:

	PR tree-optimization/118205
	* tree-parloops.cc (reduction_phi): Return NULL if PHI parameter is
	not a phi node.

gcc/testsuite/ChangeLog:

	PR tree-optimization/118205
	* c-c++-common/pr118205.c: New test.

0 files changed, 0 insertions, 0 deletions