Fix a wrong type annotation.

sdk/lib/_internal/compiler/implementation/ssa/builder.dart

Index: sdk/lib/_internal/compiler/implementation/ssa/builder.dart
diff --git a/sdk/lib/_internal/compiler/implementation/ssa/builder.dart b/sdk/lib/_internal/compiler/implementation/ssa/builder.dart
index db6608a29b8cd86eb0b41e4271eec6620443eaee..445e5e6f76ae68d75cc3d7fbf4039a67ad8a6a70 100644
--- a/sdk/lib/_internal/compiler/implementation/ssa/builder.dart
+++ b/sdk/lib/_internal/compiler/implementation/ssa/builder.dart
@@ -3118,7 +3118,7 @@ class SsaBuilder extends ResolvedVisitor implements Visitor {
     }
   }
 
-  HConstant addConstantString(Identifier node, String string) {
+  HConstant addConstantString(Node node, String string) {
     DartString dartString = new DartString.literal(string);
     Constant constant = constantSystem.createString(dartString, node);
     return graph.addConstant(constant);