Minor, move diagnostic tests for class objects
Report INVISIBLE_MEMBER on private class object usage
Report upper bounds violation for objects, not only classes
Class objects also can have delegated members
Change object resolution strategy in TypeHierarchyResolver

Instead of creating a synthetic property descriptor for objects, treat an
object as a class with a class object. This class has object's name and has no
members. The class object has all the object's members, and should be used
everywhere as a descriptor for the object declaration
Extract SpecialNames utility class
Treat anonymous objects as classes (ClassKind.CLASS)

They're not objects per se, i.e. they're not singletons
Disable "UseOfSystemOutOrSystemErr" inspection in tests
Minor refactorings in codegen tests

Unindent code, get rid of warnings, etc.
Support updated object hierarchy in JVM codegen
ClassKind.OBJECT is now almost useless in back-end

Objects are represented as classes with class objects, and back-end should work
with these class objects directly
Minor, inline method
Change object resolution strategy in lazy resolve

Objects are now treated as classes with class objects, which contain all
members, similar to TypeHierarchyResolver
Extract SpecialNames.isClassObjectName
Change object deserialization strategy

Objects are now represented as classes with class objects in deserialization as
well. Several hacks added to aid in deserializing objects, see comments around
the code. "Class" proto message now can have a synthetic class object proto
within, if it's not contained in any external class file, which is the case
with objects. "class_object_present" boolean field is deprecated and will be
dropped, since its value is equivalent to the presence of "class_object" field
Minor, use headless mode in BuiltInsSerializer
Drop "class_object_present" field from binary format

Its value is equivalent to the presence of "class_object" field
Resolve enum entries similar to objects in TypeHierarchyResolver

Enum entries are now treated as classes with class objects, instead of classes
with properties in the enum class object
Enum entries now have the type of their enum
Minor, add error message & Override