RFR(S): 8194869: [TESTBUG][aix, s390] Adapt tests to platforms.

[Lindenmaier, Goetz]

Hi,

this change adapts a row of jtreg tests to AIX. 
Shell tests often switch over all OSes, here the case for AIX was
missing. PKCSTest needs to know where the libs are on s390.

Please review.
http://cr.openjdk.java.net/~goetz/wr18/8194869-jtregAix/webrev/

Best regards,
  Goetz.