dart2js: In minified mode shorter getter and setter names.

sdk/lib/_internal/compiler/implementation/elements/modelx.dart

Index: sdk/lib/_internal/compiler/implementation/elements/modelx.dart
diff --git a/sdk/lib/_internal/compiler/implementation/elements/modelx.dart b/sdk/lib/_internal/compiler/implementation/elements/modelx.dart
index f53bfef7645801e01fec468437cbe4f993c7f7aa..7fe160cca9e5e5aa0d567073ffb0eb57d48cd003 100644
--- a/sdk/lib/_internal/compiler/implementation/elements/modelx.dart
+++ b/sdk/lib/_internal/compiler/implementation/elements/modelx.dart
@@ -262,6 +262,7 @@ class ElementX implements Element {
   bool _isNative = false;
   bool isNative() => _isNative;
   bool hasFixedBackendName() => _fixedBackendName != null;
+  bool fieldAccessNeverThrows() => false;
   String fixedBackendName() => _fixedBackendName;
   // Marks this element as a native element.
   void setNative(String name) {