aarch64: Add support for unpacked SVE MLS and MSB

aarch64: Add support for unpacked SVE MLS and MSB

This patch extends the MLS/MSB patterns to support unpacked
integer vectors.  The type suffix could be either the element
size or the container size, but using the element size should
be more efficient.

gcc/
	* config/aarch64/aarch64-sve.md (fnma<mode>4): Extend from SVE_FULL_I
	to SVE_I.
	(@aarch64_pred_fnma<mode>, cond_fnma<mode>, *cond_fnma<mode>_2)
	(*cond_fnma<mode>_4, *cond_fnma<mode>_any): Likewise.

gcc/testsuite/
	* gcc.target/aarch64/sve/mls_2.c: New test.
	* g++.target/aarch64/sve/cond_mls_1.C: Likewise.
	* g++.target/aarch64/sve/cond_mls_2.C: Likewise.
	* g++.target/aarch64/sve/cond_mls_3.C: Likewise.
	* g++.target/aarch64/sve/cond_mls_4.C: Likewise.
	* g++.target/aarch64/sve/cond_mls_5.C: Likewise.