tree-loop-distribution.c (classify_partition): Return whether a reduction appeared in all partitions and do not stop builtin...

2019-06-14  Richard Biener  <rguenther@suse.de>

	* tree-loop-distribution.c (classify_partition): Return
	whether a reduction appeared in all partitions and do not
	stop builtin detection because of this.
	(distribute_loop): Sort a non-builtin partition last if
	there's a reduction in all partitions and make sure the
	partition prevailing as last is not a builtin.

	* gcc.dg/tree-ssa/ldist-26.c: Adjust.

From-SVN: r272284