Fix issue with __proto__ when using ES6 object literals

src/ia32/full-codegen-ia32.cc

Index: src/ia32/full-codegen-ia32.cc
diff --git a/src/ia32/full-codegen-ia32.cc b/src/ia32/full-codegen-ia32.cc
index 487384c8287f092051ed847e79802ef5cd9d24f0..69fcb4dc6079aba33d1ba1821502376c08748bc5 100644
--- a/src/ia32/full-codegen-ia32.cc
+++ b/src/ia32/full-codegen-ia32.cc
@@ -2469,8 +2469,9 @@ void FullCodeGenerator::EmitClassDefineProperties(ClassLiteral* lit) {
     switch (property->kind()) {
       case ObjectLiteral::Property::CONSTANT:
       case ObjectLiteral::Property::MATERIALIZED_LITERAL:
-      case ObjectLiteral::Property::COMPUTED:
       case ObjectLiteral::Property::PROTOTYPE:
+        UNREACHABLE();
+      case ObjectLiteral::Property::COMPUTED:
         __ CallRuntime(Runtime::kDefineClassMethod, 3);
         break;
 
@@ -2481,9 +2482,6 @@ void FullCodeGenerator::EmitClassDefineProperties(ClassLiteral* lit) {
       case ObjectLiteral::Property::SETTER:
         __ CallRuntime(Runtime::kDefineSetterPropertyUnchecked, 3);
         break;
-
-      default:
-        UNREACHABLE();
     }
   }