[es6] Implement spec compliant ToPrimitive in the runtime.

src/runtime/runtime.h

Index: src/runtime/runtime.h
diff --git a/src/runtime/runtime.h b/src/runtime/runtime.h
index 18faeb8741da6f3a757de254aef325cd9167bcb0..f04325442a87a1f81a18cc3192b4c30257618e8e 100644
--- a/src/runtime/runtime.h
+++ b/src/runtime/runtime.h
@@ -491,6 +491,11 @@ namespace internal {
   F(DefineGetterPropertyUnchecked, 4, 1)             \
   F(DefineSetterPropertyUnchecked, 4, 1)             \
   F(ToObject, 1, 1)                                  \
+  F(ToPrimitive, 1, 1)                               \
+  F(ToPrimitive_Number, 1, 1)                        \
+  F(ToPrimitive_String, 1, 1)                        \
+  F(OrdinaryToPrimitive, 2, 1)                       \
+  F(ToNumber, 1, 1)                                  \
   F(StrictEquals, 2, 1)                              \
   F(InstanceOf, 2, 1)                                \
   F(HasInPrototypeChain, 2, 1)