Properly determine what classes to show in Kotlin completion:

Classes like Int and jet.Iterable should are not visible from Java
since they are erased at runtime. We call such classes non-physical,
they have to be added to completion manually.`

idea/testData/completion/class/InExpressionNoPrefix.kt

@@ -4,5 +4,6 @@ class Test {
     }
 }
 
+// RUNTIME: 1
 // EXIST: Any, Nothing, Tuple0, Int, Number
 // EXIST: Array, Math, Hashable, OutputStream

idea/testData/completion/class/InExtendTypeAnnotation.kt

@@ -3,5 +3,6 @@ class Test : <caret> {
     }
 }
 
+// RUNTIME: 1
 // EXIST: Any, Nothing, Tuple0, Int, Number
 // EXIST: Array, Math, Hashable, OutputStream