aarch64: Tweak error message for (tuple,vector) pairs

aarch64: Tweak error message for (tuple,vector) pairs

SME2 adds more intrinsics that take a tuple of vectors followed
by a single vector, with the two arguments expected to have the
same element type.  Unlike with the existing svset* intrinsics,
the size of the tuple is not fixed by the overloaded function name.

This patch adds an error message that (hopefully) copes better
with that combination.

gcc/
	* config/aarch64/aarch64-sve-builtins.cc
	(function_resolver::require_derived_vector_type): Add a specific
	error message for the case in which the caller wants a single
	vector whose element type matches a previous tuyple argument.

gcc/testsuite/
	* gcc.target/aarch64/sve/acle/general-c/set_1.c: Tweak expected
	error message.
	* gcc.target/aarch64/sve/acle/general-c/set_3.c: Likewise.
	* gcc.target/aarch64/sve/acle/general-c/set_5.c: Likewise.