Introduce "optimized_out" oddball marker for compilers.

src/types.cc

Index: src/types.cc
diff --git a/src/types.cc b/src/types.cc
index dc9bf5f61d987543963bf3154ea45f3d63cc8b5d..49c941816eb07aa72d68efe84914b411c988deff 100644
--- a/src/types.cc
+++ b/src/types.cc
@@ -191,7 +191,8 @@ Type::bitset BitsetType::Lub(i::Map* map) {
              map == heap->uninitialized_map() ||
              map == heap->no_interceptor_result_sentinel_map() ||
              map == heap->termination_exception_map() ||
-             map == heap->arguments_marker_map());
+             map == heap->arguments_marker_map() ||
+             map == heap->optimized_out_map());
       return kInternal & kTaggedPointer;
     }
     case HEAP_NUMBER_TYPE: