RFR(S): 8075858: AIX: clean-up HotSpot make files

[Volker Simonis]

Hi,

can somebody please review the following, AIX-only change:

http://cr.openjdk.java.net/~simonis/webrevs/2015/8075858
https://bugs.openjdk.java.net/browse/JDK-8075858

It's a simple clean-up of the AIX make files:

- the compiler version detection can break on systems where bash only
supports 32-bit integer compares
- there was still a bogus gcc-version check in adlc.make
- remove the -qipa options for inter-procedural link time
optimizations because they slow down the build and we don't use them
anyway.

Thank you and best regards,
Volker