This test verifies that Implementations uses the correct object when querying
local implementations. As described in golang/go#67041, a bug led to it
comparing types from different realms.

-- go.mod --
module example.com

go 1.18

-- a/a.go --
package a

type A struct{}

type Aer interface { //@loc(Aer, "Aer")
	GetA() A
}

type X struct{} //@loc(X, "X")

func (X) GetA() A

-- a/a_test.go --
package a

// Verify that we also find implementations in a test variant.
type Y struct{} //@loc(Y, "Y")

func (Y) GetA() A
-- b/b.go --
package b

import "example.com/a"

var _ a.X //@implementation("X", Aer)

var _ a.Aer //@implementation("Aer", X, Y)
