Consider:

type Foo int

//go:fix inline
type Bar = Foo

type _ struct {
	Bar
}

$ go fix --diff
--- /tmp/aa/main.go (old)
+++ /tmp/aa/main.go (new)
@@ -9,7 +9,7 @@
 type Bar = Foo

 type _ struct {
-	Bar
+	Foo
 }

Bar should never be inlined automatically (when embedded), since that changes the field name from Bar to Foo.

I noted that during the read of https://go.dev/blog/inliner where there is a mention that:

In principle the transformation should not change the program’s behavior (barring code that inspects the call stack, of course)

I assume this also is in regard to types?

CC @adonovan