dart2js: split out types from metadata.

sdk/lib/_internal/compiler/js_lib/shared/embedded_names.dart

Index: sdk/lib/_internal/compiler/js_lib/shared/embedded_names.dart
diff --git a/sdk/lib/_internal/compiler/js_lib/shared/embedded_names.dart b/sdk/lib/_internal/compiler/js_lib/shared/embedded_names.dart
index 50e0ab1ef31eb7236b853a73956eaf3842ff4d1d..26c8c84eb66e00deef4e2e94a78c3cbdae9b9b70 100644
--- a/sdk/lib/_internal/compiler/js_lib/shared/embedded_names.dart
+++ b/sdk/lib/_internal/compiler/js_lib/shared/embedded_names.dart
@@ -46,6 +46,10 @@ const IS_HUNK_INITIALIZED = 'isHunkInitialized';
 const DEFERRED_INITIALIZED = 'deferredInitialized';
 const PRECOMPILED = 'precompiled';
 
+/// A list of types used in the program e.g. for reflection or encoding of
+/// function types.
+const TYPES = 'types';
+
 /// Returns a function that creates a new Isolate (its static state).
 ///
 /// (floitsch): Note that this will probably go away, since one JS heap will