expose eternal handle api

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index c0f7a97f790a674dedff7013c5fa7bf5730a5be5..e04fbef23b4cf03407f49962df816a02ef6fe67f 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -676,6 +676,16 @@ void V8::DisposeGlobal(i::Object** obj) {
 }
 
 
+int V8::Eternalize(i::Isolate* isolate, i::Object** handle) {
+  return isolate->eternal_handles()->Create(isolate, *handle);
+}
+
+
+i::Object** V8::GetEternal(i::Isolate* isolate, int index) {
+  return isolate->eternal_handles()->Get(index).location();
+}
+
+
 // --- H a n d l e s ---