More efficient code completion + fixed a few bugs

idea/testData/completion/smart/FunctionReference11.kt.disabled

@@ -0,0 +1,19 @@
+import kotlin.platform.platformName
+
+class C(i: Int){
+    class Nested
+    inner class Inner
+
+    fun bar() {
+        foo(<caret>)
+    }
+}
+
+platformName("foo1")
+fun foo(p: () -> C.Nested){}
+
+platformName("foo2")
+fun foo(p: () -> C.Inner){}
+
+// EXIST: ::Nested
+// ABSENT: ::Inner