[Mono] Intrinsify Convert* for Vector{64, 128} on ARM64 (#65946)

* Intrinsify Convert*

* Test - comment out my change

* Enable ConvertToDouble

* Enable ConvertToInt32 and ConvertToUInt32

* Enable ConvertToInt64 and ConvertToUInt64

* Disable ConvertToInt64 and ConvertToUInt64, but enable ConvertToSingle

* Remove the support for ConvertToInt64, ConvertToUInt64 and ConvertToSingle

src/mono/mono/mini/simd-intrinsics.c

@@ -609,6 +609,9 @@ static guint16 sri_vector_methods [] = {
 	SN_AsVector4,
 	SN_Ceiling,
 	SN_ConditionalSelect,
+	SN_ConvertToDouble,
+	SN_ConvertToInt32,
+	SN_ConvertToUInt32,
 	SN_Create,
 	SN_CreateScalar,
 	SN_CreateScalarUnsafe,
@@ -802,6 +805,33 @@ emit_sri_vector (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSignature *fsi
 		return emit_simd_ins_for_sig (cfg, klass, OP_ARM64_BSL, -1, arg0_type, fsig, args);
 #else
 		return NULL;
+#endif
+	}
+	case SN_ConvertToDouble: {
+#ifdef TARGET_ARM64
+		if ((arg0_type != MONO_TYPE_I8) && (arg0_type != MONO_TYPE_U8))
+			return NULL;
+		MonoClass *arg_class = mono_class_from_mono_type_internal (fsig->params [0]);
+		int size = mono_class_value_size (arg_class, NULL);
+		int op = -1;
+		if (size == 8)
+			op = arg0_type == MONO_TYPE_I8 ? OP_ARM64_SCVTF_SCALAR : OP_ARM64_UCVTF_SCALAR;
+		else
+			op = arg0_type == MONO_TYPE_I8 ? OP_ARM64_SCVTF : OP_ARM64_UCVTF;
+		return emit_simd_ins_for_sig (cfg, klass, op, -1, arg0_type, fsig, args);
+#else
+		return NULL;
+#endif
+	}
+	case SN_ConvertToInt32: 
+	case SN_ConvertToUInt32: {
+#ifdef TARGET_ARM64
+		if (arg0_type != MONO_TYPE_R4)
+			return NULL;
+		int op = id == SN_ConvertToInt32 ? OP_ARM64_FCVTZS : OP_ARM64_FCVTZU;
+		return emit_simd_ins_for_sig (cfg, klass, op, -1, arg0_type, fsig, args);
+#else
+		return NULL;
 #endif
 	}
 	case SN_Create: {