Print the type of alias check in a dump message

Print the type of alias check in a dump message

This patch prints a message to say how an alias check is being
implemented.

2019-11-16  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-data-ref.c (create_intersect_range_checks_index)
	(create_intersect_range_checks): Print dump messages.

gcc/testsuite/
	* gcc.dg/vect/vect-alias-check-1.c: Test for the type of alias check.
	* gcc.dg/vect/vect-alias-check-8.c: Likewise.
	* gcc.dg/vect/vect-alias-check-9.c: Likewise.
	* gcc.dg/vect/vect-alias-check-10.c: Likewise.
	* gcc.dg/vect/vect-alias-check-11.c: Likewise.
	* gcc.dg/vect/vect-alias-check-12.c: Likewise.
	* gcc.dg/vect/vect-alias-check-13.c: Likewise.
	* gcc.dg/vect/vect-alias-check-14.c: Likewise.
	* gcc.dg/vect/vect-alias-check-15.c: Likewise.
	* gcc.dg/vect/vect-alias-check-16.c: Likewise.
	* gcc.dg/vect/vect-alias-check-17.c: Likewise.

From-SVN: r278353