RFR: 8229278: Improve hs_err location printing to assume less about GC internals

[Erik Österlund]

Hi,

Today when we crash and print hs_err files, the printing utility for 
describing heap locations assumes:
1) That the Java heap memory reservation is contiguous
2) That the Java heap is parseable
We should let the GC describe a location instead, opting in to such 
concepts.

This patch adds a print_location pure virtual function on CollectedHeap
allowing the GC to choose printing strategy. A new LocationPrinter 
utility was added, allowing GCs to implement the functionality easily 
without much code duplication.

Webrev:
http://cr.openjdk.java.net/~eosterlund/8229278/webrev.00/

Bug:
https://bugs.openjdk.java.net/browse/JDK-8229278

Thanks,
/Erik