aarch64: Generalise some SVE ACLE error messages

aarch64: Generalise some SVE ACLE error messages

The current SVE ACLE function-resolution diagnostics assume
that a function has a fixed choice between vectors or tuples
of vectors.  If an argument was not an SVE type at all, the
error message said the function "expects an SVE vector type"
or "expects an SVE tuple type".

This patch generalises the error to cope with cases where
an argument can be either a vector or a tuple.  It also splits
out the diagnostics for mismatched tuple sizes, so that they
can be reused by later patches.

gcc/
	* config/aarch64/aarch64-sve-builtins.h
	(function_resolver::infer_sve_type): New member function.
	(function_resolver::report_incorrect_num_vectors): Likewise.
	* config/aarch64/aarch64-sve-builtins.cc
	(function_resolver::infer_sve_type): New function,.
	(function_resolver::report_incorrect_num_vectors): New function,
	split out from...
	(function_resolver::infer_vector_or_tuple_type): ...here.  Use
	infer_sve_type.

gcc/testsuite/
	* gcc.target/aarch64/sve/acle/general-c/*: Update expected error
	messages.