Regression test for crash in hover on an alias to a built-in named type.

-- flags --
-skip_goarch=386,arm

-- go.mod --
module example.com

go 1.18

-- a/a.go --
package a

type A = error //@hover("A", "A", out)

-- @out --
```go
type A = error // size=16 (0x10)

type error interface {
	Error() string
}
```

---

@hover("A", "A", out)


```go
func (error) Error() string
```

---

[`a.A` on pkg.go.dev](https://pkg.go.dev/example.com/a#A)
