Support local variables in dart2dart.

sdk/lib/_internal/compiler/implementation/ir/ir_pickler.dart

Index: sdk/lib/_internal/compiler/implementation/ir/ir_pickler.dart
diff --git a/sdk/lib/_internal/compiler/implementation/ir/ir_pickler.dart b/sdk/lib/_internal/compiler/implementation/ir/ir_pickler.dart
index b55ab52d84426c505ee3ce516baa92affc954976..563b6b97a5306fe1114cf8ac5fe5cffa32744e62 100644
--- a/sdk/lib/_internal/compiler/implementation/ir/ir_pickler.dart
+++ b/sdk/lib/_internal/compiler/implementation/ir/ir_pickler.dart
@@ -40,7 +40,7 @@ part 'ir_unpickler.dart';
  *             | byte(NODE_INVOKE_STATIC) element selector
  *                   reference(continuation) {reference(argument)}
  *             | byte(NODE_INVOKE_CONTINUATION) reference(continuation)
- *                   reference(argument)
+ *                   {reference(argument)}
  *
  * reference ::= int(indexDelta)
  *
@@ -68,10 +68,12 @@ class Pickles {
 
   static const int FIRST_NODE_TAG           = STRING_UTF8 + 1;
   static const int NODE_CONSTANT            = FIRST_NODE_TAG;
-  static const int NODE_LET_CONT            = NODE_CONSTANT + 1;
+  static const int NODE_IS_TRUE             = NODE_CONSTANT + 1;
+  static const int NODE_LET_CONT            = NODE_IS_TRUE + 1;
   static const int NODE_INVOKE_STATIC       = NODE_LET_CONT + 1;
   static const int NODE_INVOKE_CONTINUATION = NODE_INVOKE_STATIC + 1;
-  static const int LAST_NODE_TAG            = NODE_INVOKE_CONTINUATION;
+  static const int NODE_BRANCH              = NODE_INVOKE_CONTINUATION + 1;
+  static const int LAST_NODE_TAG            = NODE_BRANCH;
 
   static const int FIRST_CONST_TAG      = LAST_NODE_TAG + 1;
   static const int CONST_BOOL           = FIRST_CONST_TAG;
@@ -173,7 +175,7 @@ class Pickler extends ir.Visitor {
     offset = 0;
     emitted = <Object, int>{};
     index = 0;
-    function.accept(this);
+    visit(function);
 
     int sizeOffset = offset;
     writeInt(emitted.length);
@@ -282,10 +284,10 @@ class Pickler extends ir.Visitor {
     writeInt(index - entryIndex);
   }
 
-  void writeBackReferenceList(List entries) {
-    writeInt(entries.length);
-    for (int i = 0; i < entries.length; i++) {
-      writeBackReference(entries[i]);
+  void writeBackReferenceList(int length, Iterable entries) {
+    writeInt(length);
+    for (var x in entries) {
+      writeBackReference(x);
     }
   }
 
@@ -364,14 +366,14 @@ class Pickler extends ir.Visitor {
       recordForBackReference(parameter);
       writeElement(parameter.element);
     }
-    node.body.accept(this);
+    visit(node.body);
   }
 
   void visitLetPrim(ir.LetPrim node) {
-    node.primitive.accept(this);
+    visit(node.primitive);
     // The right-hand side is bound in the body.
     recordForBackReference(node.primitive);
-    node.body.accept(this);
+    visit(node.body);
   }
 
   void visitLetCont(ir.LetCont node) {
@@ -384,10 +386,10 @@ class Pickler extends ir.Visitor {
     writeInt(node.continuation.parameters.length);
     // The continuation is bound in the body.
     recordForBackReference(node.continuation);
-    node.body.accept(this);
+    visit(node.body);
     // The continuation parameters are bound in the continuation's body.
     node.continuation.parameters.forEach(recordForBackReference);
-    node.continuation.body.accept(this);
+    visit(node.continuation.body);
   }
 
   void visitInvokeStatic(ir.InvokeStatic node) {
@@ -397,14 +399,22 @@ class Pickler extends ir.Visitor {
     // TODO(lry): compact encoding when the arity of the selector and the
     // arguments list are the same
     writeBackReference(node.continuation.definition);
-    writeBackReferenceList(node.arguments.map(
-        (a) => a.definition).toList(growable: false));
+    writeBackReferenceList(node.arguments.length,
+                           node.arguments.map((a) => a.definition));
   }
 
   void visitInvokeContinuation(ir.InvokeContinuation node) {
     writeByte(Pickles.NODE_INVOKE_CONTINUATION);
     writeBackReference(node.continuation.definition);
-    writeBackReference(node.argument.definition);
+    writeBackReferenceList(node.arguments.length,
+                           node.arguments.map((a) => a.definition));
+  }
+
+  void visitBranch(ir.Branch node) {
+    writeByte(Pickles.NODE_BRANCH);
+    visit(node.condition);
+    writeBackReference(node.trueContinuation.definition);
+    writeBackReference(node.falseContinuation.definition);
   }
 
   void visitConstant(ir.Constant node) {
@@ -412,6 +422,11 @@ class Pickler extends ir.Visitor {
     node.value.accept(constantPickler);
   }
 
+  void visitIsTrue(ir.IsTrue node) {
+    writeByte(Pickles.NODE_IS_TRUE);
+    writeBackReference(node.value.definition);
+  }
+
   void visitNode(ir.Node node) {
     throw "Unexpected $node in pickler.";
   }