This test exercises stub methods functionality with variadic parameters.

In golang/go#61693 stubmethods was panicking in this case.

-- go.mod --
module mod.com

go 1.18
-- main.go --
package main

type C int

func F(err ...error) {}

func _() {
	var x error
	F(x, C(0)) //@suggestedfix(re"C.0.", re"missing method Error", stub)
}
-- @stub/main.go --
--- before
+++ after
@@ -3 +3,6 @@
-type C int
+type C int
+
+// Error implements error.
+func (C) Error() string {
+	panic("unimplemented")
+}
