Make builtin_vectorized_function take a combined_fn

Make builtin_vectorized_function take a combined_fn

This patch replaces the fndecl argument to builtin_vectorized_function
with a combined_fn and gets the vectoriser to call it for internal
functions too.  The patch also moves vectorisation of machine-specific
built-ins to a new hook, builtin_md_vectorized_function.

Tested on x86_64-linux-gnu, aarch64-linux-gnu, arm-linux-gnu and
powerpc64-linux-gnu.

gcc/
	* target.def (builtin_vectorized_function): Take a combined_fn (in
	the form of an unsigned int) rather than a function decl.
	(builtin_md_vectorized_function): New.
	* targhooks.h (default_builtin_vectorized_function): Replace the
	fndecl argument with an unsigned int.
	(default_builtin_md_vectorized_function): Declare.
	* targhooks.c (default_builtin_vectorized_function): Replace the
	fndecl argument with an unsigned int.
	(default_builtin_md_vectorized_function): New function.
	* doc/tm.texi.in (TARGET_VECTORIZE_BUILTIN_MD_VECTORIZED_FUNCTION):
	New hook.
	* doc/tm.texi: Regenerate.
	* tree-vect-stmts.c (vectorizable_function): Update call to
	builtin_vectorized_function, also passing internal functions.
	Call builtin_md_vectorized_function for target-specific builtins.
	* config/aarch64/aarch64-protos.h
	(aarch64_builtin_vectorized_function): Replace fndecl argument
	with an unsigned int.
	* config/aarch64/aarch64-builtins.c: Include case-cfn-macros.h.
	(aarch64_builtin_vectorized_function): Update after above changes.
	Use CASE_CFN_*.
	* config/arm/arm-protos.h (arm_builtin_vectorized_function): Replace
	fndecl argument with an unsigned int.
	* config/arm/arm-builtins.c: Include case-cfn-macros.h
	(arm_builtin_vectorized_function): Update after above changes.
	Use CASE_CFN_*.
	* config/i386/i386.c: Include case-cfn-macros.h
	(ix86_veclib_handler): Take a combined_fn rather than a
	built_in_function.
	(ix86_veclibabi_svml, ix86_veclibabi_acml): Likewise.  Use
	mathfn_built_in rather than calling builtin_decl_implicit directly.
	(ix86_builtin_vectorized_function) Update after above changes.
	Use CASE_CFN_*.
	* config/rs6000/rs6000.c: Include case-cfn-macros.h
	(rs6000_builtin_vectorized_libmass): Replace fndecl argument
	with a combined_fn.  Use CASE_CFN_*.  Use mathfn_built_in rather
	than calling builtin_decl_implicit directly.
	(rs6000_builtin_vectorized_function): Update after above changes.
	Use CASE_CFN_*.  Move BUILT_IN_MD to...
	(rs6000_builtin_md_vectorized_function): ...this new function.
	(TARGET_VECTORIZE_BUILTIN_MD_VECTORIZED_FUNCTION): Define.

From-SVN: r230491