RFR: 8246256: GenerateLinkOptData should not mutate the interim or bootstrap JDK

[Claes Redestad]

Hi,

the classlist generation mutates the interim JDK, which is usually
part of the things we build, but can also be an external bootstrap JDK
that we shouldn't write to. Fix is to explicitly generate the files to
explicit locations in the build directory.

Sponsoring the fix Fedor suggested here:

https://mail.openjdk.java.net/pipermail/build-dev/2020-May/027537.html

Bug:    https://bugs.openjdk.java.net/browse/JDK-8246256
Webrev: http://cr.openjdk.java.net/~redestad/8246256/open.00/

Testing: built and verified locally, tier1 ongoing

Thanks!

/Claes