Implement string interpolation up to SSA.

dart/frog/leg/compiler.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class WorkElement {
   final Element element;
   TreeElements resolutionTree;
   Function run;
 
   WorkElement.toCompile(this.element) : resolutionTree = null {
@@ skipping 52 matching lines @@
     generator = new SsaCodeGeneratorTask(this);
     emitter = new CodeEmitterTask(this);
     tasks = [scanner, parser, resolver, checker, builder, optimizer, generator,
              emitter];
   }
 
   void ensure(bool condition) {
     if (!condition) cancel('failed assertion in leg');
   }
 
-  void unimplemented(String methodName) {
-    cancel("$methodName not implemented");
+  void unimplemented(String methodName,
+                     [Node node, Token token, HInstruction instruction]) {
+    cancel("$methodName not implemented", node, token, instruction);
   }
 
   void cancel([String reason, Node node, Token token,
                HInstruction instruction]) {
     throw new CompilerCancelledException(reason);
   }
 
   void log(message) {
     // Do nothing.
   }
@@ skipping 147 matching lines @@
 
 class CompilerCancelledException {
   final String reason;
   CompilerCancelledException(this.reason);
 
   String toString() {
     String banner = 'compiler cancelled';
     return (reason !== null) ? '$banner: $reason' : '$banner';
   }
 }