Implement correct scoping rules for variables.

sdk/lib/_internal/compiler/implementation/warnings.dart

Index: sdk/lib/_internal/compiler/implementation/warnings.dart
diff --git a/sdk/lib/_internal/compiler/implementation/warnings.dart b/sdk/lib/_internal/compiler/implementation/warnings.dart
index 7e641bf8e24746377dd9696f4a5cca16abc41801..0cffa3ea82b6e4f29da854358e875c1ae30e9aa2 100644
--- a/sdk/lib/_internal/compiler/implementation/warnings.dart
+++ b/sdk/lib/_internal/compiler/implementation/warnings.dart
@@ -809,12 +809,12 @@ Length: #{length}''');
       const MessageKind(
           "Error: Top-level variable cannot be declared static.");
 
-  static const MessageKind REFERENCE_IN_INITIALIZATION = const MessageKind(
-       "Error: Variable '#{variableName}' is referenced during its "
-       "initialization.",
-       howToFix: "If you are trying to reference a shadowed variable, rename"
+  static const MessageKind ACCESS_BEFORE_INITIALIZATION = const MessageKind(
+      "Error: Variable '#{variableName}' is referenced before its "
+      "initialization.",
+      howToFix: "If you are trying to reference a shadowed variable, rename"
          " one of the variables.",
-       examples: const ["""
+      examples: const ["""
 foo(t) {
   var t = t;
   return t;