RFR(M): 8076163: ppc: port "8074345: Enable RewriteBytecodes when VM runs with CDS"

[Lindenmaier, Goetz]

Hi,

This change ports the platform changes required after "8074345: Enable RewriteBytecodes
when VM runs with CDS" to ppc.  Ppc does not support CDS, but the changes are required
anyways, as new methods need to be implemented.

Please review this change.  It would be great if I can push this soon, if possible before
8074345 is transported to jdk9/hs.
http://cr.openjdk.java.net/~goetz/webrevs/8076163-tmpTbl/webrev.00/

Best regards,
  Goetz.