[AArch64] Make call insns record the callee's arm_pcs

[AArch64] Make call insns record the callee's arm_pcs

At the moment we rely on SYMBOL_REF_DECL to get the ABI of the callee
of a call insn, falling back to the default ABI if the decl isn't
available.  I think it'd be cleaner to attach the ABI directly to the
call instruction instead, which would also have the very minor benefit
of handling indirect calls more efficiently.

2019-10-01  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/aarch64-protos.h (aarch64_expand_call): Take an
	extra callee_abi argument.
	* config/aarch64/aarch64.c (aarch64_expand_call): Likewise.
	Insert a CALLEE_ABI unspec into the call pattern as the second
	element in the PARALLEL.
	(aarch64_simd_call_p): Delete.
	(aarch64_insn_callee_abi): Get the arm_pcs of the callee from
	the new CALLEE_ABI element of the PARALLEL.
	(aarch64_init_cumulative_args): Get the arm_pcs of the callee
	from the function type, if given.
	(aarch64_function_arg_advance): Handle ARM_PCS_SIMD.
	(aarch64_function_arg): Likewise.  Return the arm_pcs of the callee
	when passed the function_arg_info end marker.
	(aarch64_output_mi_thunk): Pass the arm_pcs of the callee as the
	final argument of gen_sibcall.
	* config/aarch64/aarch64.md (UNSPEC_CALLEE_ABI): New unspec.
	(call): Make operand 2 a const_int_operand and pass it to expand_call.
	Wrap it in an UNSPEC_CALLEE_ABI unspec for the dummy define_expand
	pattern.
	(call_value): Likewise operand 3.
	(sibcall): Likewise operand 2.  Place the unspec before rather than
	after the return.
	(sibcall_value): Likewise operand 3.
	(*call_insn, *call_value_insn): Include an UNSPEC_CALLEE_ABI.
	(tlsgd_small_<mode>, *tlsgd_small_<mode>): Likewise.
	(*sibcall_insn, *sibcall_value_insn): Likewise.  Remove empty
	constraint strings.
	(untyped_call): Pass const0_rtx as the callee ABI to gen_call.

gcc/testsuite/
	* gcc.target/aarch64/torture/simd-abi-10.c: New test.
	* gcc.target/aarch64/torture/simd-abi-11.c: Likewise.

From-SVN: r276391