Recent enhancements to the fatal error handling have been made in the SE Embedded products and we want to contribute that work back into the main Hotspot code base.

This CR adds hsfind (debug.cpp) functionality to the fatal error handler (os::print_location) to treat each register as a pointer and see what it appears to point to. It primarily involves:

- adding/converting print methods to be print_on(stream st) methods
- making those print methods available in product not just debug

This means it had a somewhat viral affect in terms of number of files changed.

The print_location calls occur from the print_context method which is os-cpu specific (unfortunately - and unnecessarily if we had a reasonable abstraction for accessing registers in the context).

print_context is itself only called when the fatal error occurs due to a crash (SEGV etc) rather than internal errors (asserts, guarantees)