Replace 'class object' with 'default object' in renderers and test data

Includes changes to decompiled text
Old syntax is used in builtins and project code for now

compiler/testData/diagnostics/tests/redeclarations/EnumEntriesAndClassObjectMembers.kt

@@ -3,7 +3,7 @@ enum class E {
 
     <!REDECLARATION!>SECOND<!>
 
-    class object {
+    default object {
         class <!REDECLARATION!>FIRST<!>
 
         val <!REDECLARATION!>SECOND<!> = this

compiler/testData/diagnostics/tests/redeclarations/EnumEntriesAndClassObjectMembers.txt

@@ -29,7 +29,7 @@ internal final enum class E : kotlin.Enum<E> {
     public final override /*1*/ /*fake_override*/ fun ordinal(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
-    internal class object Default {
+    internal default object Default {
         private constructor Default()
         internal final val SECOND: E.Default
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean

compiler/testData/diagnostics/tests/redeclarations/PropertyAndInnerClass.kt

@@ -5,7 +5,7 @@ public class A() {
 }
 
 public class B() {
-   class object {
+   default object {
       public val <!REDECLARATION!>FOO<!>: String = "test"
       
       public class <!REDECLARATION!>FOO<!>() { }

compiler/testData/diagnostics/tests/redeclarations/PropertyAndInnerClass.txt

@@ -21,7 +21,7 @@ public final class B {
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
-    public class object Default {
+    public default object Default {
         private constructor Default()
         public final val FOO: kotlin.String = "test"
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean

compiler/testData/diagnostics/tests/redeclarations/kt2247.kt

@@ -1,9 +1,9 @@
-//KT-2247 Report name clashes between inner classes and members of class object
+//KT-2247 Report name clashes between inner classes and members of default object
 
 package kt2247
 
 class B {
-    class object {
+    default object {
         class <!REDECLARATION!>Y<!> {
         }
     }

compiler/testData/diagnostics/tests/redeclarations/kt2247.txt

@@ -8,7 +8,7 @@ package kt2247 {
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
-        internal class object Default {
+        internal default object Default {
             private constructor Default()
             public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
             public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int

compiler/testData/diagnostics/tests/redeclarations/kt2438.kt

@@ -12,7 +12,7 @@ class B {
 class A {
     class <!REDECLARATION!>B<!>
     
-    class object {
+    default object {
         class <!REDECLARATION!>B<!>
         class <!REDECLARATION!>B<!>
     }

compiler/testData/diagnostics/tests/redeclarations/kt2438.txt

@@ -22,7 +22,7 @@ package kt2438 {
             public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
         }
 
-        internal class object Default {
+        internal default object Default {
             private constructor Default()
             public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
             public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int