This test checks that we correctly determine pkgsite links for various
identifiers.

We should only produce links that work, meaning the object is reachable via the
package's public API.
-- go.mod --
module mod.com

go 1.18
-- p.go --
package p

type E struct {
	Embed int
}

// T is in the package scope, and so should be linkable.
type T struct{ //@hover("T", "T", T)
	// Only exported fields should be linkable

	f int //@hover("f", "f", f)
	F int //@hover("F", "F", F)

	E

	// TODO(rfindley): is the link here correct? It ignores N.
	N struct {
		// Nested fields should also be linkable.
		Nested int //@hover("Nested", "Nested", Nested)
	}
}
// M is an exported method, and so should be linkable.
func (T) M() {}

// m is not exported, and so should not be linkable.
func (T) m() {}

func _() {
	var t T

	// Embedded fields should be linkable.
	_ = t.Embed //@hover("Embed", "Embed", Embed)

	// Local variables should not be linkable, even if they are capitalized.
	var X int //@hover("X", "X", X)
	_ = X

	// Local types should not be linkable, even if they are capitalized.
	type Local struct { //@hover("Local", "Local", Local)
		E
	}

	// But the embedded field should still be linkable.
	var l Local
	_ = l.Embed //@hover("Embed", "Embed", Embed)
}
-- @Embed/hover.md --
```go
field Embed int
```

[`(p.E).Embed` on pkg.go.dev](https://pkg.go.dev/mod.com#E.Embed)
-- @F/hover.md --
```go
field F int
```

@hover("F", "F", F)


[`(p.T).F` on pkg.go.dev](https://pkg.go.dev/mod.com#T.F)
-- @Local/hover.md --
```go
type Local struct {
	E
}
```

Local types should not be linkable, even if they are capitalized.
-- @Nested/hover.md --
```go
field Nested int
```

Nested fields should also be linkable.
-- @T/hover.md --
```go
type T struct {
	f int //@hover("f", "f", f)
	F int //@hover("F", "F", F)

	E

	// TODO(rfindley): is the link here correct? It ignores N.
	N struct {
		// Nested fields should also be linkable.
		Nested int //@hover("Nested", "Nested", Nested)
	}
}

func (T).M()
func (T).m()
```

T is in the package scope, and so should be linkable.


[`p.T` on pkg.go.dev](https://pkg.go.dev/mod.com#T)
-- @X/hover.md --
```go
var X int
```

Local variables should not be linkable, even if they are capitalized.
-- @f/hover.md --
```go
field f int
```

@hover("f", "f", f)