Fix and refactor ExpressionCodegen#pushClosureOnStack

- change Closure parameter to ClassDescriptor, load closure in the beginning
- invert and rename boolean parameter, also use it only to prevent pushing
  dispatch receiver (not the extension receiver) onto the stack because the
  only non-trivial usage of it is preceded by manual handling of the dispatch
  (not extension) receiver. This fixes innerOfLocalCaptureExtensionReceiver.kt

compiler/testData/codegen/box/localClasses/localClassCaptureExtensionReceiver.kt

@@ -0,0 +1,14 @@
+class Outer {
+    fun String.id(): String {
+        class Local(unused: Long) {
+            fun result() = this@id
+            fun outer() = this@Outer
+        }
+
+        return Local(42L).result()
+    }
+
+    fun result(): String = "OK".id()
+}
+
+fun box() = Outer().result()