[dev.go2go] cmd/go2go: document that function-local parameterized typ…

…es don't work

For #39643

Change-Id: Ic3d3e4a4bd46c62705d3ce3473e3e06e1380d834
Reviewed-on: https://go-review.googlesource.com/c/go/+/238620
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/go2go/doc.go

@@ -36,7 +36,8 @@
 // Because this tool generates Go files, and because instantiated types
 // and functions need to refer to the types with which they are instantiated,
 // using function-local types as type arguments is not supported.
-// This is a deficiency of the tool, it will not be a deficiency in
+// Similarly, function-local parameterized types do not work.
+// These are deficiencies of the tool, they will work as expected in
 // any complete implementation.
 //
 // Because this tool generates Go files, and because it generates type