RFR (M): 8220301: Remove jbyte use in CardTable (affects all platforms)

[Kim Barrett]

> On Mar 12, 2019, at 12:32 PM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
> On Mon, 2019-03-11 at 15:29 -0400, Kim Barrett wrote:
>> 
>> I'm concerned about changing the signed-ness of card table entries.
>> jbyte is signed.  There may be code that expects or assumes signed
>> values.  One place of particular concern would be assembly code
>> generators, where we might be generating sign-extending loads.
>> 
>> Note that I didn't actually spot any signed-ness problems, but they
>> would be easy to miss.
> 
> I haven't spotted anything either.

I spent some more time looking for and not finding any.  And tests are passing,
so I guess I’ll stop worrying.

> http://cr.openjdk.java.net/~tschatzl/8220301/webrev.1_to_2/ (diff)
> http://cr.openjdk.java.net/~tschatzl/8220301/webrev.2/ (full)
> 
> webrevs.
> 
> Thanks,
>  Thomas

Looks good.