Add transform test

lib/std/zig/parser_test.zig

@@ -9,6 +9,18 @@ test "zig fmt: change @typeOf to @TypeOf" {
     );
 }
 
+// TODO: Remove nakedcc/stdcallcc once zig 0.6.0 is released. See https://github.com/ziglang/zig/pull/3977
+test "zig fmt: convert nakedcc/stdcallcc into callconv(...)" {
+    try testTransform(
+        \\nakedcc fn foo1() void {}
+        \\stdcallcc fn foo2() void {}
+    ,
+        \\fn foo1() callconv(.Naked) void {}
+        \\fn foo2() callconv(.Stdcall) void {}
+        \\
+    );
+}
+
 test "zig fmt: comptime struct field" {
     try testCanonical(
         \\const Foo = struct {