aarch64: testsuite: Fix do-assemble tests for SME

aarch64: testsuite: Fix do-assemble tests for SME

GCC doesn't support SME without SVE2, so the -march=armv8-a+<ext> argument to
check_no_compiler_messages causes aarch64_asm_<ext>_ok to return zero for SME
and any <ext> that implies it.  This patch changes the baseline architecure to
armv9-a for these extensions.

The tests for ACLE SME2 intrinsics that require FEAT_FAMINMAX were configured
to do-assemble if aarch64_asm_sme2_ok returned 1 (by default), but they really
need to check if +faminmax is supported too.  The fix above exposed this, so
we also fix the do-assemble/do-compile choice for those tests here.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/sme2/acle-asm/amax_f16_x2.c: Gate do-assemble on
	assembler support for +faminmax and +sme2.
	* gcc.target/aarch64/sme2/acle-asm/amax_f16_x4.c: Likewise.
	* gcc.target/aarch64/sme2/acle-asm/amax_f32_x2.c: Likewise.
	* gcc.target/aarch64/sme2/acle-asm/amax_f32_x4.c: Likewise.
	* gcc.target/aarch64/sme2/acle-asm/amax_f64_x2.c: Likewise.
	* gcc.target/aarch64/sme2/acle-asm/amax_f64_x4.c: Likewise.
	* gcc.target/aarch64/sme2/acle-asm/amin_f16_x2.c: Likewise.
	* gcc.target/aarch64/sme2/acle-asm/amin_f16_x4.c: Likewise.
	* gcc.target/aarch64/sme2/acle-asm/amin_f32_x2.c: Likewise.
	* gcc.target/aarch64/sme2/acle-asm/amin_f32_x4.c: Likewise.
	* gcc.target/aarch64/sme2/acle-asm/amin_f64_x2.c: Likewise.
	* gcc.target/aarch64/sme2/acle-asm/amin_f64_x4.c: Likewise.
	* lib/target-supports.exp: Split the extensions that require SME into
	a separate set, and use armv9-a as their baseline.