Introduce ClassKind#CLASS_OBJECT and ClassKind#isObject and usages.

Rename LazyClassDescriptor#onlyEnumEntries -> enumClassObjectInfo.
Determine ClassKind in JetClassInfo and JetObjectInfo constructor.
Remove complex constructor for enum entry in enum test.
Logic simplified in LazyClassMemberScope.
Minor refactorings.

compiler/testData/lazyResolve/namespaceComparator/enum.kt

@@ -2,6 +2,5 @@ package test
 
 enum class Test(a : Int) {
   A : Test(0)
-  B(x : Int) : Test(x)
-  C : Test(0) {}
+  B : Test(0) {}
 }