Finish refactoring FixProcessor to use ChangeBuilder

pkg/analysis_server/test/services/correction/fix_test.dart

Index: pkg/analysis_server/test/services/correction/fix_test.dart
diff --git a/pkg/analysis_server/test/services/correction/fix_test.dart b/pkg/analysis_server/test/services/correction/fix_test.dart
index 86bbad9f026564fceb930080c185fcfcf921f525..ce3f8c20ecd3efa238ec8e12e35e0efd56637fa0 100644
--- a/pkg/analysis_server/test/services/correction/fix_test.dart
+++ b/pkg/analysis_server/test/services/correction/fix_test.dart
@@ -4530,7 +4530,7 @@ main() {
   test(throw 42);
 }
 
-void test(arg0) {
+void test(param0) {
 }
 ''');
   }
@@ -4733,7 +4733,7 @@ main() {
   test(null);
 }
 
-void test(arg0) {
+void test(param0) {
 }
 ''');
   }
@@ -5102,7 +5102,7 @@ class A<T> {
 }
 
 class B {
-  dynamic compute() {}
+  compute() {}
 }
 ''');
   }