Address review comments.

Author: Gabor Horvath

test/Interop/Cxx/foreign-reference/extensions.swift

@@ -3,10 +3,30 @@
 
 import ReferenceCounted
 
+protocol MyProto {
+    func foo() -> Self
+    func bar() -> Self
+}
+
 extension NS.LocalCount {
     static func g() {}
 
     public func f() {
         Self.g()
     }
 }
+
+extension NS.LocalCount {
+    public func foo() -> Self {
+        return self
+    }
+
+    public func bar() -> NS.LocalCount {
+        return self
+    }
+}
+
+let x = NS.LocalCount.create()
+x.f()
+let _ = x.foo()
+let _ = x.bar()