Merging JEP 483 (Ahead-of-Time Class Loading & Linking) review into a single PR

[ioi.lam at oracle.com]

Now that the review of JEP 483 is winding down, I have created a 
combined branch of all the 7 individual PRs. This will make it easy for 
me to sync from the mainline before making the final integration.

- https://github.com/openjdk/jdk/pull/21642

I have addressed most of the feedback in the individual PRs. I will 
address any outstanding feedback in the combined PR.

Please take a look again at the combined PR and give your approval if 
you think the code is OK :-)


(I will close the individual PRs. If I see any new comments on them, I 
will copy-and-paste into the combined one.)


Thanks

- Ioi