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

compiler/testData/psi/examples/PolymorphicClassObjects.kt

@@ -9,7 +9,7 @@ open class Buildable {
 
 class List<T> {
 
-  default object : Buildable {
+  companion object : Buildable {
     override fun newBuilder<E, R>() : Builder<E, R>
 
   }

compiler/testData/psi/examples/PolymorphicClassObjects.txt

@@ -133,7 +133,7 @@ JetFile: PolymorphicClassObjects.kt
       PsiWhiteSpace('\n\n  ')
       OBJECT_DECLARATION
         MODIFIER_LIST
-          PsiElement(default)('default')
+          PsiElement(companion)('companion')
         PsiWhiteSpace(' ')
         PsiElement(object)('object')
         PsiWhiteSpace(' ')

compiler/testData/psi/examples/UpdateOperation.kt

@@ -1,5 +1,5 @@
 class Pair(x : Int, y : Int) {
-  default object {
+  companion object {
     fun copy(from : Pair, x : Int = from.x, y : Int = from.y) = Pair(x, y)
   }
 }

compiler/testData/psi/examples/UpdateOperation.txt

@@ -34,7 +34,7 @@ JetFile: UpdateOperation.kt
       PsiWhiteSpace('\n  ')
       OBJECT_DECLARATION
         MODIFIER_LIST
-          PsiElement(default)('default')
+          PsiElement(companion)('companion')
         PsiWhiteSpace(' ')
         PsiElement(object)('object')
         PsiWhiteSpace(' ')