feat(arch): the ZCNOT unary pair and the vector counter step

Assisted-by: GLM 5.3 Flash

asm/extension_test.go

@@ -234,8 +234,10 @@ func TestExtensionNamesARM64(t *testing.T) {
 		"ZBIC",
 		"ZCLS",
 		"ZCLZ",
+		"ZCNOT",
 		"ZCNT",
 		"ZCOMPACT",
+		"ZDECP",
 		"ZDUP",
 		"ZEOR",
 		"ZEXPAND",
@@ -491,7 +493,7 @@ func TestExtensionNamesARM64(t *testing.T) {
 	if strings.Join(got, ",") != strings.Join(want, ",") {
 		t.Errorf("ExtensionNames(ARM64) = %v, want %v", got, want)
 	}
-	if n := len(arch.Extensions(arch.ARM64)); n != 500 {
-		t.Errorf("the family registers %d instructions, want 500", n)
+	if n := len(arch.Extensions(arch.ARM64)); n != 503 {
+		t.Errorf("the family registers %d instructions, want 503", n)
 	}
 }