RFR: 8275445: RunThese30M.java failed "assert(ZAddress::is_marked(addr)) failed: Should be marked" [v2]

[Markus Grönlund]

> Greetings,
> 
> This fixes the issue seen in testing when accessing an oop as part of unloading (introduced with [JDK-8266936](https://bugs.openjdk.java.net/browse/JDK-8266936)).
> 
> Instead, oop accesses will be done outside of unloading and the result, i.e the codesource attribute, will be cached and reused in the FinalizerEntry.
> 
> Testing: in progress
> 
> Thanks
> Markus
> 
> PS one effect of this is that classes that unload before they have allocated anything will not have a codesource attribute. This can be fixed by letting classes register with the table as part of class loading, instead of during allocation. I will follow-up with a separate change for that.

Markus Grönlund has updated the pull request incrementally with one additional commit since the last revision:

  header

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6001/files
  - new: https://git.openjdk.java.net/jdk/pull/6001/files/a5de3988..7b17ff5f

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6001&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6001&range=00-01

  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6001.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6001/head:pull/6001

PR: https://git.openjdk.java.net/jdk/pull/6001