RFR: 8230203: Replace markWord enums with uintptr_t constants

[Kim Barrett]

> On Aug 27, 2019, at 4:06 PM, Stefan Karlsson <stefan.karlsson at oracle.com> wrote:
> 
> Hi Kim,
> 
> I think your comments makes sense. I have an updated webrev that changes some of the types:
> 
>  https://cr.openjdk.java.net/~stefank/8230203/webrev.02.delta/
>  https://cr.openjdk.java.net/~stefank/8230203/webrev.02/
> 
> The new patch compiles on Linux x64 and not yet tested. I'll run it through testing if you think this is the right change.

This looks good to me.