[modules] Remove dead code.

TBR=adamk@chromium.org
BUG=v8:1569

Review-Url: https://codereview.chromium.org/2621413009
Cr-Commit-Position: refs/heads/master@{#42325}

src/objects.h

@@ -8053,8 +8053,6 @@ class Module : public Struct {
   static const int kSize = kRequestedModulesOffset + kPointerSize;
 
  private:
-  enum { kEvaluatedBit };
-
   static void CreateExport(Handle<Module> module, int cell_index,
                            Handle<FixedArray> names);
   static void CreateIndirectExport(Handle<Module> module, Handle<String> name,