isolates refactor: this change introduces 'dart:isolate' as a library. This is a

runtime/vm/bootstrap.h

Index: runtime/vm/bootstrap.h
diff --git a/runtime/vm/bootstrap.h b/runtime/vm/bootstrap.h
index 48100d18c8a2adcbe45918fa824849c9a1b3c48d..3c27b27a7799e8786f00d4edea252f1b3ad42de9 100644
--- a/runtime/vm/bootstrap.h
+++ b/runtime/vm/bootstrap.h
@@ -21,10 +21,12 @@ class Bootstrap : public AllStatic {
   static RawScript* LoadImplScript();
   static RawError* Compile(const Library& library, const Script& script);
   static void SetupNativeResolver();
+  static RawError* InitAdditionalLibraries();
 
  private:
   static const char corelib_source_[];
   static const char corelib_impl_source_[];
+  static const char isolate_source_[];
 };
 
 }  // namespace dart