aarch64: Support SVE comparisons for unpacked integers

aarch64: Support SVE comparisons for unpacked integers

This patch adds support for comparing unpacked SVE integer vectors,
such as byte elements stored in the bottom bytes of halfword
containers.  It also adds support for selects between unpacked
SVE vectors (both integer and floating-point), since selects and
compares are closely tied via the vcond optab interface.

gcc/
	* config/aarch64/aarch64-sve.md (@vcond_mask_<mode><vpred>): Extend
	from SVE_FULL to SVE_ALL.
	(*vcond_mask_<mode><vpred>): Likewise.
	(@aarch64_sel_dup<mode>): Likewise.
	(vcond<SVE_FULL:mode><v_int_equiv>): Extend to...
	(vcond<SVE_ALL:mode><SVE_I:mode>): ...this, but requiring the
	sizes of the container modes to match.
	(vcondu<SVE_FULL:mode><v_int_equiv>): Extend to...
	(vcondu<SVE_ALL:mode><SVE_I:mode>): ...this.
	(vec_cmp<SVE_FULL_I:mode><vpred>): Extend to...
	(vec_cmp<SVE_I:mode><vpred>): ...this.
	(vec_cmpu<SVE_FULL_I:mode><vpred>): Extend to...
	(vec_cmpu<SVE_I:mode><vpred>): ...this.
	(@aarch64_pred_cmp<cmp_op><SVE_FULL_I:mode>): Extend to...
	(@aarch64_pred_cmp<cmp_op><SVE_I:mode>): ...this.
	(*cmp<cmp_op><SVE_FULL_I:mode>_cc): Extend to...
	(*cmp<cmp_op><SVE_I:mode>_cc): ...this.
	(*cmp<cmp_op><SVE_FULL_I:mode>_ptest): Extend to...
	(*cmp<cmp_op><SVE_I:mode>_ptest): ...this.
	(*cmp<cmp_op><SVE_FULL_I:mode>_and): Extend to...
	(*cmp<cmp_op><SVE_I:mode>_and): ...this.

gcc/testsuite/
	* gcc.target/aarch64/sve/cmp_1.c: New test.
	* gcc.target/aarch64/sve/cmp_2.c: Likewise.
	* gcc.target/aarch64/sve/cond_arith_1.c: Add --param
	aarch64-sve-compare-costs=0
	* gcc.target/aarch64/sve/cond_arith_1_run.c: Likewise.
	* gcc.target/aarch64/sve/cond_arith_3.c: Likewise.
	* gcc.target/aarch64/sve/cond_arith_3_run.c: Likewise.
	* gcc.target/aarch64/sve/mask_gather_load_7.c: Likewise.
	* gcc.target/aarch64/sve/mask_load_slp_1.c: Likewise.
	* gcc.target/aarch64/sve/vcond_11.c: Likewise.
	* gcc.target/aarch64/sve/vcond_11_run.c: Likewise.