Remove requiredTypes

pkg/compiler/lib/src/compiler.dart

Index: pkg/compiler/lib/src/compiler.dart
diff --git a/pkg/compiler/lib/src/compiler.dart b/pkg/compiler/lib/src/compiler.dart
index 9c7995aa321fd7abeafb25a15ff95e1e88fd3e24..2415006ed0012b05b2e488d76d01fc163119c2b7 100644
--- a/pkg/compiler/lib/src/compiler.dart
+++ b/pkg/compiler/lib/src/compiler.dart
@@ -1553,6 +1553,12 @@ class _CompilerCoreTypes implements CoreTypes {
   }
 
   @override
+  InterfaceType get stackTraceType {
+    stackTraceClass.ensureResolved(resolution);
+    return stackTraceClass.rawType;
+  }
+
+  @override
   InterfaceType iterableType([DartType elementType]) {
     iterableClass.ensureResolved(resolution);
     InterfaceType type = iterableClass.rawType;