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/regressions/kt3647.kt

@@ -1,7 +1,7 @@
 // KT-3647 Unexpected compilation error: "Expression is inaccessible from a nested class"
 
 class Test(val value: Int) {
-    class object {
+    default object {
         fun create(init: () -> Int): Test {
             return Test(init())
         }

compiler/testData/diagnostics/tests/regressions/kt3647.txt

@@ -7,7 +7,7 @@ internal final class Test {
     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()
         internal final fun create(/*0*/ init: () -> kotlin.Int): Test
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean

compiler/testData/diagnostics/tests/regressions/kt394.kt

@@ -1,9 +1,9 @@
-// KT-394 Make class object members visible inside the owning class
+// KT-394 Make default object members visible inside the owning class
 
 class X() {
 //    class Y {}
 
-    class object{
+    default object{
         class Y() {}
     }
 

compiler/testData/diagnostics/tests/regressions/kt394.txt

@@ -7,7 +7,7 @@ internal final class X {
     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/regressions/kt526UnresolvedReferenceInnerStatic.kt

@@ -4,7 +4,7 @@
 package demo
 
 class Foo {
-    class object {
+    default object {
         class Bar() { }
     }
 }

compiler/testData/diagnostics/tests/regressions/kt526UnresolvedReferenceInnerStatic.txt

@@ -8,7 +8,7 @@ package demo {
         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/regressions/kt575.kt

@@ -1,9 +1,9 @@
-// KT-575 Cannot ++ a class object member
+// KT-575 Cannot ++ a default object member
 
 package kt575
 
 class Creature() {
-    class object {
+    default object {
         var numCreated : Int = 0
           private set
     }

compiler/testData/diagnostics/tests/regressions/kt575.txt

@@ -24,7 +24,7 @@ package kt575 {
             public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
         }
 
-        internal class object Default {
+        internal default object Default {
             private constructor Default()
             internal final var numCreated: kotlin.Int
             public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean

compiler/testData/diagnostics/tests/regressions/kt588.kt

@@ -1,7 +1,7 @@
 // KT-588 Unresolved static method
 
 class Test() : Thread("Test") {
-    class object {
+    default object {
         fun init2() {
 
         }

compiler/testData/diagnostics/tests/regressions/kt588.txt

@@ -71,7 +71,7 @@ internal final class Test : java.lang.Thread {
     invisible_fake open override /*1*/ /*fake_override*/ fun suspend0(): kotlin.Unit
     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/regressions/kt701.kt

@@ -2,7 +2,7 @@
 fun getJavaClass<T>() : java.lang.Class<T> { return "" <!CAST_NEVER_SUCCEEDS!>as<!> Class<T> }
 
 public class Throwables() {
-    class object {
+    default object {
         public fun propagateIfInstanceOf<X : Throwable?>(throwable : Throwable?, declaredType : Class<X<!BASE_WITH_NULLABLE_UPPER_BOUND!>?<!>>?) {
             if (((throwable != null) && declaredType?.isInstance(throwable)!!))
             {

compiler/testData/diagnostics/tests/regressions/kt701.txt

@@ -8,7 +8,7 @@ public final class Throwables {
     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 open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int