Start resolving classes and default constructors.

frog/leg/ssa/builder.dart

Index: frog/leg/ssa/builder.dart
===================================================================
--- frog/leg/ssa/builder.dart	(revision 2023)
+++ frog/leg/ssa/builder.dart	(working copy)
@@ -500,7 +500,7 @@
       case ">":   push(new HGreater(target, left, right)); break;
       case ">=":  push(new HGreaterEqual(target, left, right)); break;
       default: compiler.unimplemented("SsaBuilder.visitBinary");
-    }    
+    }
   }
 
   visitSend(Send node) {
@@ -521,7 +521,7 @@
         visit(node.receiver);
         visit(node.argumentsNode);
         var right = pop();
-        var left = pop();        
+        var left = pop();
         visitBinary(left, op, right, element);
       }
     } else if (node.isPropertyAccess) {
@@ -561,6 +561,10 @@
     }
   }
 
+  visitNewExpression(NewExpression node) {
+    compiler.unimplemented("SsaBuilder: new expression");
+  }
+
   HInstruction updateDefinition(Node node, HInstruction value) {
     VariableElement element = elements[node];
     value = guard(element.type, value);