example$ head -99 $(find . -type f)
==> ./go.mod <==
module example.com

go 1.12

==> ./a/a.go <==
package a

type A int

func (A) F() {}

==> ./b/b.go <==
package b

import (
	"example.com/a"
	"example.com/c"
)

type B interface{ F() }

var _ B = a.A(0)
var _ B = c.C(0)

var _ = B.F

==> ./c/c.go <==
package c

type C int

func (C) F() {}

==> ./d/d.go <==
package d

import "example.com/b"

var _ interface{} = b.B.F

example$ ../xtools/gopls-v0.7.5  references   ./a/a.go:#33 
/Users/adonovan/w/example/b/b.go:13:11-12
/Users/adonovan/w/example/d/d.go:5:25-26
example$ ../xtools/gopls-v0.11.0 references   ./a/a.go:#33 
/Users/adonovan/w/example/b/b.go:13:11-12
/Users/adonovan/w/example/d/d.go:5:25-26
example$ ../xtools/gopls.head  references   ./a/a.go:#33 
/Users/adonovan/w/example/d/d.go:5:25-26