Throw a runtime error when trying to call a constructor of a class that could not be resolved.

corelib/src/exceptions.dart

Index: corelib/src/exceptions.dart
diff --git a/corelib/src/exceptions.dart b/corelib/src/exceptions.dart
index 2c72deea8e42a098010da46227bea17c09b0ad8f..3a47566757f9c5cf2b440023a42e851caaff46e4 100644
--- a/corelib/src/exceptions.dart
+++ b/corelib/src/exceptions.dart
@@ -194,3 +194,12 @@ class IntegerDivisionByZeroException implements Exception {
   const IntegerDivisionByZeroException();
   String toString() => "IntegerDivisionByZeroException";
 }
+
+/**
+ * Exception thrown when a runtime error occurs.
+ */
+class RuntimeError implements Exception {
+  final message;
+  RuntimeError(this.message);
+  String toString() => "RuntimeError: $message";
+}