Made dart2js constructor lookup logic "private"-aware, fixed 4740 bug.

lib/compiler/implementation/universe/universe.dart

Index: lib/compiler/implementation/universe/universe.dart
diff --git a/lib/compiler/implementation/universe/universe.dart b/lib/compiler/implementation/universe/universe.dart
index ef9500b56b45f9cb9801bee93a26fcc0863ec3ab..473d1b645428cb547be73a324521e0a5272cc350 100644
--- a/lib/compiler/implementation/universe/universe.dart
+++ b/lib/compiler/implementation/universe/universe.dart
@@ -123,6 +123,7 @@ class Selector {
   final SelectorKind kind;
   final SourceString name;
   final LibraryElement library; // Library is null for non-private selectors.
+  final SourceString normalizedConstructorName;

[kasperl, 2012/10/08 08:06:41]

It would indeed be great to get rid of this and use an empty name for default
constructors and the name of the constructor for the others. I'm okay with
trying that out in another CL.

[aam-me, 2012/10/09 04:08:42]

Done.

 
   // The numbers of arguments of the selector. Includes named arguments.
   final int argumentCount;
@@ -134,13 +135,15 @@ class Selector {
       SourceString name,
       LibraryElement library,
       this.argumentCount,
-      [List<SourceString> namedArguments = const <SourceString>[]])
+      [List<SourceString> namedArguments = const <SourceString>[],
+      SourceString normalizedConstructorName = null])
     : this.name = name,
       this.library = name.isPrivate() ? library : null,
       this.namedArguments = namedArguments,
       this.orderedNamedArguments = namedArguments.isEmpty()
           ? namedArguments
-          : <SourceString>[] {
+          : <SourceString>[],
+      this.normalizedConstructorName = normalizedConstructorName {
     assert(!name.isPrivate() || library != null);
   }
 
@@ -187,6 +190,20 @@ class Selector {
       : this(SelectorKind.CALL, Compiler.CALL_OPERATOR_NAME, null,
              selector.argumentCount, selector.namedArguments);
 
+  Selector.callConstructor(SourceString className,
+                           SourceString constructorName,
+                           LibraryElement library)
+      : this(SelectorKind.CALL,
+             constructorName,
+             library,
+             0,
+             const [],
+             Elements.constructConstructorName(className, constructorName));
+
+  Selector.callDefaultConstructor(SourceString name,
+                                  LibraryElement library)
+      : this(SelectorKind.CALL, name, library, 0, const [], name);
+
   // TODO(kasperl): This belongs somewhere else.
   Selector.noSuchMethod()
       : this(SelectorKind.CALL, Compiler.NO_SUCH_METHOD, null, 2);