Track computed literal properties.

src/property-details.h

Index: src/property-details.h
diff --git a/src/property-details.h b/src/property-details.h
index 6d0f1479d1e0da38cd59a9263458e97217749a24..669b05dca051d8feefa413410f2afb666b5c3979 100644
--- a/src/property-details.h
+++ b/src/property-details.h
@@ -113,7 +113,7 @@ class Representation {
   bool is_more_general_than(const Representation& other) const {
     ASSERT(kind_ != kExternal);
     ASSERT(other.kind_ != kExternal);
-    if (IsHeapObject()) return other.IsDouble();
+    if (IsHeapObject()) return other.IsDouble() || other.IsNone();
     return kind_ > other.kind_;
   }
 
@@ -213,6 +213,7 @@ class PropertyDetails BASE_EMBEDDED {
   }
 
   Representation representation() {
+    ASSERT(type() != NORMAL);
     return DecodeRepresentation(RepresentationField::decode(value_));
   }