Repository rebased

[Per Liden]

Hi all,

FYI, I just rebased the zgc/zgc repo on to the latest jdk/hs. Note that 
we're using a kind of rebase-model rather then the pure merge-model for 
zgc/zgc. This means we always keep the ZGC pages on top of what's 
upstream. When we rebase we also tend to collapse patches into the ZGC 
master patch and bump its version number.

We've used this model through out the ZGC development, and it's been 
working well for us. It makes it easy to get an overview of what code 
ZGC is touching and it makes it easier for us to maintain a clear and 
up-to-date set of "upstream" patches. The full history for all patches 
is of course still available in the old (and now merged) branches in hg.

You don't need to do anything special, just do the normal "hg pull -u" 
to get the latest stuff. There's no history re-write happening on the 
server side or anything like that (we're not doing that kind of rebase).

cheers,
Per