RFR (XS) 8059904: libjvm_db.c warnings in solaris/sparc build with SS

[serguei.spitsyn at oracle.com]

Please, review the fix for:
   https://bugs.openjdk.java.net/browse/JDK-8059904


Open webrev:
http://cr.openjdk.java.net/~sspitsyn/webrevs/2014/hotspot/8059904-jvmdb-warn.1/


Summary:

   Several warnings started to appear at compilation of the libjvm_db.c
   after the switch from Sun C++ 5.10 to 5.12.
   The fix is to cast the result of calloc() to the correct type.


Testing:
   Running the adhoc pstack tests on Solaris sparcv9 and amd64


Thanks,
Serguei