[8/n] PR85694: Make patterns check for target support

[8/n] PR85694: Make patterns check for target support

This patch makes pattern recognisers do their own checking for vector
types and target support.  Previously some recognisers did this
themselves and some left it to vect_pattern_recog_1.

Doing this means we can get rid of the type_in argument, which was
ignored if the recogniser did its own checking.  It also means
we create fewer junk statements.

2018-06-20  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-vectorizer.h (NUM_PATTERNS, vect_recog_func_ptr): Move to
	tree-vect-patterns.c.
	* tree-vect-patterns.c (vect_supportable_direct_optab_p): New function.
	(vect_recog_dot_prod_pattern): Use it.  Remove the type_in argument.
	(vect_recog_sad_pattern): Likewise.
	(vect_recog_widen_sum_pattern): Likewise.
	(vect_recog_pow_pattern): Likewise.  Check for a null vectype.
	(vect_recog_widen_shift_pattern): Remove the type_in argument.
	(vect_recog_rotate_pattern): Likewise.
	(vect_recog_mult_pattern): Likewise.
	(vect_recog_vector_vector_shift_pattern): Likewise.
	(vect_recog_divmod_pattern): Likewise.
	(vect_recog_mixed_size_cond_pattern): Likewise.
	(vect_recog_bool_pattern): Likewise.
	(vect_recog_mask_conversion_pattern): Likewise.
	(vect_try_gather_scatter_pattern): Likewise.
	(vect_recog_widen_mult_pattern): Likewise.  Check for a null vectype.
	(vect_recog_over_widening_pattern): Likewise.
	(vect_recog_gather_scatter_pattern): Likewise.
	(vect_recog_func_ptr): Move from tree-vectorizer.h
	(vect_vect_recog_func_ptrs): Move further down the file.
	(vect_recog_func): Likewise.  Remove the third argument.
	(NUM_PATTERNS): Define based on vect_vect_recog_func_ptrs.
	(vect_pattern_recog_1): Expect the pattern function to do any
	necessary target tests.  Also expect it to provide a vector type.
	Remove the type_in handling.

From-SVN: r261791