RFR(S) 8249276 CDS archived objects must have "neutral" markwords

[coleen.phillimore at oracle.com]

150 
archived_oop->set_mark_raw(markWord::prototype().copy_set_hash(hash_original));


This seems very specific to the content of MarkWord, but it seems like 
the content and meaning of markWord is splashed all over the vm so it's 
fine.

The change looks good.

Coleen

On 7/27/20 1:20 AM, Ioi Lam wrote:
> https://bugs.openjdk.java.net/browse/JDK-8249276
> http://cr.openjdk.java.net/~iklam/jdk16/8249276-reset-archive-obj-headers.v01/ 
>
>
> Please review this change (initial patch provided by David Holmes; I 
> rearranged it a little and added more comments).
>
> We reinitialize the markWord of all archived objects to remove any 
> side effect of GC/locking/etc during "java -Xshare:dump".
>
> (David mentioned in the bug comments about assertions inside the 
> identity_hash() call, but maybe this should be fixed in a different bug?)
>
> Tested with mach5 tiers 1-4.
>
> Thanks
> - Ioi