Minor: fix spelling warnings
Refactoring: remove state
Refactoring: extract method
Always create descriptors for class object psi element in lazy resolve

KT-4397 Exception: @NotNull method org/jetbrains/jet/lang/resolve/lazy/ResolveSession.getClassDescriptor must not return null

 #KT-4397 Fixed
Fix @Nullable annotation for JetClassObject.getObjectDeclaration()