Implement modular compilation

lib/src/js_ast/printer.dart

Index: lib/src/js_ast/printer.dart
diff --git a/lib/src/js/printer.dart b/lib/src/js_ast/printer.dart
similarity index 99%
rename from lib/src/js/printer.dart
rename to lib/src/js_ast/printer.dart
index 955f6d9cbf2a008b9ba05668b3602dbf4bfc4d87..87a104f364f3e774831d49589422dd795d7bf6bb 100644
--- a/lib/src/js/printer.dart
+++ b/lib/src/js_ast/printer.dart
@@ -1270,10 +1270,25 @@ class Printer extends TypeScriptTypePrinter implements NodeVisitor {
   }
 
   visitNameSpecifier(NameSpecifier node) {
-    out(node.name);
+    if (node.isStar) {
+      out('*');
+    } else {
+      var importName = node.name.name;
+      out(importName);
+
+      if (node.asName == null) {
+        // If our local was renamed, generate an implicit "as".
+        // This is a convenience feature so imports can be renamed.
+        var localName = localNamer.getName(node.name);
+        if (localName != importName) {
+          out(' as ');
+          out(localName);
+        }
+      }
+    }
     if (node.asName != null) {
       out(' as ');
-      out(node.asName);
+      visitIdentifier(node.asName);
     }
   }