RFR: 8202435: [aix] print program break as part of memory info into hs-err file

Hi all, may I please have reviews for this tiny, AIX-specific enhancement. bug: https://bugs.openjdk.java.net/browse/JDK-8202435 webrev: http://cr.openjdk.java.net/~stuefe/webrevs/8202435-aix-print-program-break/w... It prints out program break information as part of os::print_memory_info().