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

compiler/testData/diagnostics/tests/resolve/invoke/kt3833-invokeInsideNestedClass.kt

@@ -1,4 +1,4 @@
-//KT-3833 Invoke method not working inside default object?
+//KT-3833 Invoke method not working inside companion object?
 package m
 
 class Either1 {
@@ -26,7 +26,7 @@ object Foo{
 }
 
 class C{
-    default object {
+    companion object {
         fun f(){
             Foo.v()
         }

compiler/testData/diagnostics/tests/resolve/invoke/kt3833-invokeInsideNestedClass.txt

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