d: Add TARGET_D_REGISTER_CPU_TARGET_INFO

d: Add TARGET_D_REGISTER_CPU_TARGET_INFO

This implements `__traits(getTargetInfo, "floatAbi")' for all targets
that have D support files.

gcc/ChangeLog:

	* config/aarch64/aarch64-d.c (aarch64_d_handle_target_float_abi): New
	function.
	(aarch64_d_register_target_info): New function.
	* config/aarch64/aarch64-protos.h (aarch64_d_register_target_info):
	Declare.
	* config/aarch64/aarch64.h (TARGET_D_REGISTER_CPU_TARGET_INFO):
	Define.
	* config/arm/arm-d.c (arm_d_handle_target_float_abi): New function.
	(arm_d_register_target_info): New function.
	* config/arm/arm-protos.h (arm_d_register_target_info): Declare.
	* config/arm/arm.h (TARGET_D_REGISTER_CPU_TARGET_INFO): Define.
	* config/i386/i386-d.c (ix86_d_handle_target_float_abi): New function.
	(ix86_d_register_target_info): New function.
	* config/i386/i386-protos.h (ix86_d_register_target_info): Declare.
	* config/i386/i386.h (TARGET_D_REGISTER_CPU_TARGET_INFO): Define.
	* config/mips/mips-d.c (mips_d_handle_target_float_abi): New function.
	(mips_d_register_target_info): New function.
	* config/mips/mips-protos.h (mips_d_register_target_info): Declare.
	* config/mips/mips.h (TARGET_D_REGISTER_CPU_TARGET_INFO): Define.
	* config/pa/pa-d.c (pa_d_handle_target_float_abi): New function.
	(pa_d_register_target_info): New function.
	* config/pa/pa-protos.h (pa_d_register_target_info): Declare.
	* config/pa/pa.h (TARGET_D_REGISTER_CPU_TARGET_INFO): Define.
	* config/riscv/riscv-d.c (riscv_d_handle_target_float_abi): New
	function.
	(riscv_d_register_target_info): New function.
	* config/riscv/riscv-protos.h (riscv_d_register_target_info): Declare.
	* config/riscv/riscv.h (TARGET_D_REGISTER_CPU_TARGET_INFO): Define.
	* config/rs6000/rs6000-d.c (rs6000_d_handle_target_float_abi): New
	function.
	(rs6000_d_register_target_info): New function.
	* config/rs6000/rs6000-protos.h (rs6000_d_register_target_info):
	Declare.
	* config/rs6000/rs6000.h (TARGET_D_REGISTER_CPU_TARGET_INFO): Define.
	* config/s390/s390-d.c (s390_d_handle_target_float_abi): New function.
	(s390_d_register_target_info): New function.
	* config/s390/s390-protos.h (s390_d_register_target_info): Declare.
	* config/s390/s390.h (TARGET_D_REGISTER_CPU_TARGET_INFO): Define.
	* config/sparc/sparc-d.c (sparc_d_handle_target_float_abi): New
	function.
	(sparc_d_register_target_info): New function.
	* config/sparc/sparc-protos.h (sparc_d_register_target_info): Declare.
	* config/sparc/sparc.h (TARGET_D_REGISTER_CPU_TARGET_INFO): Define.
	* doc/tm.texi: Regenerate.
	* doc/tm.texi.in (D language and ABI): Add @hook for
	TARGET_D_REGISTER_CPU_TARGET_INFO.

gcc/d/ChangeLog:

	* d-target.cc (Target::_init): Call new targetdm hook to register CPU
	specific target info keys.
	* d-target.def (d_register_cpu_target_info): New hook.