[AArch64] Split built-in function codes into major and minor codes

[AArch64] Split built-in function codes into major and minor codes

It was easier to add the SVE ACLE support without enumerating every
function at build time.  This in turn meant that it was easier if the
SVE builtins occupied a distinct numberspace from the existing AArch64
ones, which *are* enumerated at build time.  This patch therefore
divides the built-in functions codes into "major" and "minor" codes.
At present the major code is just "general", but the SVE patch will add
"SVE" as well.

Also, it was convenient to put the SVE ACLE support in its own file,
so the patch makes aarch64.c provide the frontline target hooks directly,
forwarding to the other files for the real work.

The reason for organising the files this way is that aarch64.c needs
to define the target hook macros whatever happens, and having aarch64.c
macros forward to aarch64-builtins.c functions and aarch64-bulitins.c
functions forward to the SVE file seemed a bit indirect.  Doing things
the way the patch does them puts aarch64-builtins.c and the SVE code on
more of an equal footing.

The aarch64_(general_)gimple_fold_builtin change is mostly just
reindentation.

2019-09-27  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/aarch64-protos.h (aarch64_builtin_class): New enum.
	(AARCH64_BUILTIN_SHIFT, AARCH64_BUILTIN_CLASS): New constants.
	(aarch64_gimple_fold_builtin, aarch64_mangle_builtin_type)
	(aarch64_fold_builtin, aarch64_init_builtins, aarch64_expand_builtin):
	(aarch64_builtin_decl, aarch64_builtin_rsqrt): Delete.
	(aarch64_general_mangle_builtin_type, aarch64_general_init_builtins):
	(aarch64_general_fold_builtin, aarch64_general_gimple_fold_builtin):
	(aarch64_general_expand_builtin, aarch64_general_builtin_decl):
	(aarch64_general_builtin_rsqrt): Declare.
	* config/aarch64/aarch64-builtins.c (aarch64_general_add_builtin):
	New function.
	(aarch64_mangle_builtin_type): Rename to...
	(aarch64_general_mangle_builtin_type): ...this.
	(aarch64_init_fcmla_laneq_builtins, aarch64_init_simd_builtins)
	(aarch64_init_crc32_builtins, aarch64_init_builtin_rsqrt)
	(aarch64_init_pauth_hint_builtins, aarch64_init_tme_builtins): Use
	aarch64_general_add_builtin instead of add_builtin_function.
	(aarch64_init_builtins): Rename to...
	(aarch64_general_init_builtins): ...this.  Use
	aarch64_general_add_builtin instead of add_builtin_function.
	(aarch64_builtin_decl): Rename to...
	(aarch64_general_builtin_decl): ...this and remove the unused
	arguments.
	(aarch64_expand_builtin): Rename to...
	(aarch64_general_expand_builtin): ...this and remove the unused
	arguments.
	(aarch64_builtin_rsqrt): Rename to...
	(aarch64_general_builtin_rsqrt): ...this.
	(aarch64_fold_builtin): Rename to...
	(aarch64_general_fold_builtin): ...this.  Take the function subcode
	and return type as arguments.  Remove the "ignored" argument.
	(aarch64_gimple_fold_builtin): Rename to...
	(aarch64_general_gimple_fold_builtin): ...this.  Take the function
	subcode and gcall as arguments, and return the new function call.
	* config/aarch64/aarch64.c (aarch64_init_builtins)
	(aarch64_fold_builtin, aarch64_gimple_fold_builtin)
	(aarch64_expand_builtin, aarch64_builtin_decl): New functions.
	(aarch64_builtin_reciprocal): Call aarch64_general_builtin_rsqrt
	instead of aarch64_builtin_rsqrt.
	(aarch64_mangle_type): Call aarch64_general_mangle_builtin_type
	instead of aarch64_mangle_builtin_type.

From-SVN: r276177