Refactor: process mentions of class object

Rename usages that refer to "default object" concept now
Test data file names are left as is

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/JvmAbi.java

@@ -46,7 +46,7 @@ public final class JvmAbi {
 
     //TODO: To be removed after kotlin M11
     @Deprecated
-    public static final String DEPRECATED_CLASS_OBJECT_FIELD = "OBJECT$";
+    public static final String DEPRECATED_DEFAULT_OBJECT_FIELD = "OBJECT$";
 
     @NotNull
     public static String getSyntheticMethodNameForAnnotatedProperty(@NotNull Name propertyName) {

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/AbstractBinaryClassAnnotationAndConstantLoader.kt

@@ -159,7 +159,7 @@ public abstract class AbstractBinaryClassAnnotationAndConstantLoader<A : Any, C
         val classKind = Flags.CLASS_KIND[classProto.getFlags()]
         val classId = nameResolver.getClassId(classProto.getFqName())
         if (classKind == ProtoBuf.Class.Kind.CLASS_OBJECT && isStaticFieldInOuter(proto)) {
-            // Backing fields of properties of a class object are generated in the outer class
+            // Backing fields of properties of a default object are generated in the outer class
             return kotlinClassFinder.findKotlinClass(classId.getOuterClassId())
         }
         else if (classKind == ProtoBuf.Class.Kind.TRAIT && annotatedCallableKind == AnnotatedCallableKind.PROPERTY) {