[AArch64] Testsuite markup for SVE

[AArch64] Testsuite markup for SVE

This patch adds new target selectors for SVE and updates existing
selectors accordingly.  It also XFAILs some tests that don't yet
work for some SVE modes; most of these go away with follow-on
vectorisation enhancements.

2018-01-13  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/testsuite/
	* lib/target-supports.exp (check_effective_target_aarch64_sve)
	(aarch64_sve_bits, check_effective_target_aarch64_sve_hw)
	(aarch64_sve_hw_bits, check_effective_target_aarch64_sve256_hw):
	New procedures.
	(check_effective_target_vect_perm): Handle SVE.
	(check_effective_target_vect_perm_byte): Likewise.
	(check_effective_target_vect_perm_short): Likewise.
	(check_effective_target_vect_widen_sum_hi_to_si_pattern): Likewise.
	(check_effective_target_vect_widen_mult_qi_to_hi): Likewise.
	(check_effective_target_vect_widen_mult_hi_to_si): Likewise.
	(check_effective_target_vect_element_align_preferred): Likewise.
	(check_effective_target_vect_align_stack_vars): Likewise.
	(check_effective_target_vect_load_lanes): Likewise.
	(check_effective_target_vect_masked_store): Likewise.
	(available_vector_sizes): Use aarch64_sve_bits for SVE.
	* gcc.dg/vect/tree-vect.h (VECTOR_BITS): Define appropriately
	for SVE.
	* gcc.dg/tree-ssa/ssa-dom-cse-2.c: Add SVE XFAIL.
	* gcc.dg/vect/bb-slp-pr69907.c: Likewise.
	* gcc.dg/vect/no-vfa-vect-depend-2.c: Likewise.
	* gcc.dg/vect/no-vfa-vect-depend-3.c: Likewise.
	* gcc.dg/vect/slp-23.c: Likewise.
	* gcc.dg/vect/slp-perm-5.c: Likewise.
	* gcc.dg/vect/slp-perm-6.c: Likewise.
	* gcc.dg/vect/slp-perm-9.c: Likewise.
	* gcc.dg/vect/slp-reduc-3.c: Likewise.
	* gcc.dg/vect/vect-114.c: Likewise.
	* gcc.dg/vect/vect-mult-const-pattern-1.c: Likewise.
	* gcc.dg/vect/vect-mult-const-pattern-2.c: Likewise.

Reviewed-by: James Greenhalgh <james.greenhalgh@arm.com>
Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r256613