This test verifies that gopls can remove unused parameters from methods.

Specifically, check
1. basic removal of unused parameters, when the receiver is named, locally and
   across package boundaries
2. handling of unnamed receivers

-- flags --
-min_go=go1.20

-- go.mod --
module example.com/rm

go 1.20

-- basic.go --
package rm

type Basic int

func (t Basic) Foo(x int) { //@codeaction("x", "x", "refactor.rewrite.removeUnusedParam", basic)
}

func _(b Basic) {
	b.Foo(1)
	// TODO(rfindley): methodexprs should not get rewritten as methods.
	Basic.Foo(1, 2)
}

-- basicuse/p.go --
package basicuse

import "example.com/rm"

func _() {
	x := new(rm.Basic)
	x.Foo(sideEffects())
	rm.Basic.Foo(1,2)
}

func sideEffects() int

-- @basic/basic.go --
package rm

type Basic int

func (t Basic) Foo() { //@codeaction("x", "x", "refactor.rewrite.removeUnusedParam", basic)
}

func _(b Basic) {
	b.Foo()
	// TODO(rfindley): methodexprs should not get rewritten as methods.
	Basic(1).Foo()
}
-- @basic/basicuse/p.go --
package basicuse

import "example.com/rm"

func _() {
	x := new(rm.Basic)
	var (
		t rm.Basic = *x
		_ int      = sideEffects()
	)
	t.Foo()
	rm.Basic(1).Foo()
}

func sideEffects() int
-- missingrecv.go --
package rm

type Missing struct{}

var r2 int

func (Missing) M(a, b, c, r0 int) (r1 int) { //@codeaction("b", "b", "refactor.rewrite.removeUnusedParam", missingrecv)
	return a + c
}

func _() {
	m := &Missing{}
	_ = m.M(1, 2, 3, 4)
}

-- missingrecvuse/p.go --
package missingrecvuse

import "example.com/rm"

func _() {
	x := rm.Missing{}
	x.M(1, sideEffects(), 3, 4)
}

func sideEffects() int

-- @missingrecv/missingrecv.go --
package rm

type Missing struct{}

var r2 int

func (Missing) M(a, c, r0 int) (r1 int) { //@codeaction("b", "b", "refactor.rewrite.removeUnusedParam", missingrecv)
	return a + c
}

func _() {
	m := &Missing{}
	_ = (*m).M(1, 3, 4)
}
-- @missingrecv/missingrecvuse/p.go --
package missingrecvuse

import "example.com/rm"

func _() {
	x := rm.Missing{}
	var _ int = sideEffects()
	x.M(1, 3, 4)
}

func sideEffects() int