RFR(M): 8204965: Fix '--disable-cds' and disable CDS on AIX by default

[Volker Simonis]

Hi,

can I please have a review for the following fix:

http://cr.openjdk.java.net/~simonis/webrevs/2018/8204965/
https://bugs.openjdk.java.net/browse/JDK-8204965

CDS does currently not work on AIX because of the way how we
reserve/commit memory on AIX. The problem is that we're using a
combination of shmat/mmap depending on the page size and the size of
the memory chunk to reserve. This makes it impossible to reliably
reserve the memory for the CDS archive and later on map the various
parts of the archive into these regions.

In order to fix this we would have to completely rework the memory
reserve/commit/uncommit logic on AIX which is currently out of our
scope because of resource limitations.

Unfortunately, I could not simply disable CDS in the configure step
because some of the shared code apparently relies on parts of the CDS
code which gets excluded from the build when CDS is disabled. So I
also fixed the offending parts in hotspot and cleaned up the configure
logic for CDS.

Thank you and best regards,
Volker

PS: I did run the job through the submit forest
(mach5-one-simonis-JDK-8204965-20180613-1946-26349) but the results
weren't really useful because they mention build failures on linux-x64
which I can't reproduce locally.