RFR: 8242626: enhance posix print_rlimit_info

[Baesken, Matthias]

Please review this small enhancement of  os::Posix::print_rlimit_info.

It adds  return code handling  of  getrlimit ,  output of some more limit values and  output of  hard limits (additionally to the existing soft limits) .

Bug/webrev :

https://bugs.openjdk.java.net/browse/JDK-8242626

http://cr.openjdk.java.net/~mbaesken/webrevs/8242626.1/

Thanks, Matthias