arm: [MVE intrinsics] rework vstr scatter_base_wb

arm: [MVE intrinsics] rework vstr scatter_base_wb

Implement vstr?q_scatter_base_wb using the new MVE builtins framework.

The patch introduces a new 'b' type for signatures, which
represents the type of the 'base' argument of vstr?q_scatter_base_wb.

gcc/ChangeLog:

	* config/arm/arm-builtins.cc (arm_strsbwbs_qualifiers)
	(arm_strsbwbu_qualifiers, arm_strsbwbs_p_qualifiers)
	(arm_strsbwbu_p_qualifiers): Delete.
	* config/arm/arm-mve-builtins-base.cc (vstrq_scatter_base_impl):
	Add support for MODE_wb.
	* config/arm/arm-mve-builtins-shapes.cc (parse_type): Add support
	for 'b' type.
	(store_scatter_base): Add support for MODE_wb.
	* config/arm/arm-mve-builtins.cc
	(function_resolver::require_pointer_to_type): New.
	* config/arm/arm-mve-builtins.h
	(function_resolver::require_pointer_to_type): New.
	* config/arm/arm_mve.h (vstrdq_scatter_base_wb): Delete.
	(vstrdq_scatter_base_wb_p): Delete.
	(vstrwq_scatter_base_wb_p): Delete.
	(vstrwq_scatter_base_wb): Delete.
	(vstrdq_scatter_base_wb_p_s64): Delete.
	(vstrdq_scatter_base_wb_p_u64): Delete.
	(vstrdq_scatter_base_wb_s64): Delete.
	(vstrdq_scatter_base_wb_u64): Delete.
	(vstrwq_scatter_base_wb_p_s32): Delete.
	(vstrwq_scatter_base_wb_p_f32): Delete.
	(vstrwq_scatter_base_wb_p_u32): Delete.
	(vstrwq_scatter_base_wb_s32): Delete.
	(vstrwq_scatter_base_wb_u32): Delete.
	(vstrwq_scatter_base_wb_f32): Delete.
	(__arm_vstrdq_scatter_base_wb_s64): Delete.
	(__arm_vstrdq_scatter_base_wb_u64): Delete.
	(__arm_vstrdq_scatter_base_wb_p_s64): Delete.
	(__arm_vstrdq_scatter_base_wb_p_u64): Delete.
	(__arm_vstrwq_scatter_base_wb_p_s32): Delete.
	(__arm_vstrwq_scatter_base_wb_p_u32): Delete.
	(__arm_vstrwq_scatter_base_wb_s32): Delete.
	(__arm_vstrwq_scatter_base_wb_u32): Delete.
	(__arm_vstrwq_scatter_base_wb_f32): Delete.
	(__arm_vstrwq_scatter_base_wb_p_f32): Delete.
	(__arm_vstrdq_scatter_base_wb): Delete.
	(__arm_vstrdq_scatter_base_wb_p): Delete.
	(__arm_vstrwq_scatter_base_wb_p): Delete.
	(__arm_vstrwq_scatter_base_wb): Delete.
	* config/arm/arm_mve_builtins.def (vstrwq_scatter_base_wb_u)
	(vstrdq_scatter_base_wb_u, vstrwq_scatter_base_wb_p_u)
	(vstrdq_scatter_base_wb_p_u, vstrwq_scatter_base_wb_s)
	(vstrwq_scatter_base_wb_f, vstrdq_scatter_base_wb_s)
	(vstrwq_scatter_base_wb_p_s, vstrwq_scatter_base_wb_p_f)
	(vstrdq_scatter_base_wb_p_s): Delete.
	* config/arm/iterators.md (supf): Remove VSTRWQSBWB_S,
	VSTRWQSBWB_U, VSTRDQSBWB_S, VSTRDQSBWB_U.
	(VSTRDSBQ, VSTRWSBWBQ, VSTRDSBWBQ): Delete.
	* config/arm/mve.md (mve_vstrwq_scatter_base_wb_<supf>v4si): Delete.
	(mve_vstrwq_scatter_base_wb_p_<supf>v4si): Delete.
	(mve_vstrwq_scatter_base_wb_fv4sf): Delete.
	(mve_vstrwq_scatter_base_wb_p_fv4sf): Delete.
	(mve_vstrdq_scatter_base_wb_<supf>v2di): Delete.
	(mve_vstrdq_scatter_base_wb_p_<supf>v2di): Delete.
	(@mve_vstrq_scatter_base_wb_<mode>): New.
	(@mve_vstrq_scatter_base_wb_p_<mode>): New.
	* config/arm/unspecs.md (VSTRWQSBWB_S, VSTRWQSBWB_U, VSTRWQSBWB_F)
	(VSTRDQSBWB_S, VSTRDQSBWB_U): Delete.
	(VSTRSBWBQ, VSTRSBWBQ_P): New.