default -> companion: replace all mentions of default and default object

compiler/testData/codegen/box/enum/classObjectInEnum.kt

@@ -3,7 +3,7 @@ enum class Game {
     PAPER
     SCISSORS
 
-    default object {
+    companion object {
         fun foo() = ROCK
         val bar = PAPER
     }

compiler/testData/codegen/box/enum/inclassobj.kt

@@ -1,8 +1,8 @@
-fun box() = if(Context.operatingSystemType == Context.Default.OsType.OTHER) "OK" else "fail"
+fun box() = if(Context.operatingSystemType == Context.Companion.OsType.OTHER) "OK" else "fail"
 
 public class Context
 {
-        default object
+        companion object
         {
                 public enum class OsType {
                         LINUX;

compiler/testData/codegen/box/enum/innerWithExistingClassObject.kt

@@ -1,5 +1,5 @@
 class A {
-    default object {}
+    companion object {}
     enum class E {
         OK
     }