slp: upgrade complex add to new format and fix memory leaks

slp: upgrade complex add to new format and fix memory leaks

This fixes a memory leak in complex_add_pattern because I was not calling
vect_free_slp_tree when dissolving one side of the TWO_OPERANDS nodes.

Secondly it also upgrades the class to the new inteface required by the other
patterns.

gcc/ChangeLog:

	* tree-vect-slp-patterns.c (class complex_pattern,
	class complex_add_pattern): Add parameters to matches.
	(complex_add_pattern::build): Free memory.
	(complex_add_pattern::matches): Move validation end of match.
	(complex_add_pattern::recognize): Likewise.