1. namespace class should not be accessible from Kotlin despite the fact we don't have kotlin class descriptor for it.

2. testdata is corrected due to the fact frontend has wrong qualified name in trace for root namespace

idea/testData/completion/basic/ExtendClassName.kt

@@ -1,3 +1,5 @@
+namespace foo
+
 open class MySecondClass() {
 }
 
@@ -10,4 +12,4 @@ class A() : My<caret> {
     }
 }
 
-// EXIST: MySecondClass, MyFirstClass
+// EXIST: MySecondClass, MyFirstClass