The ShowSafepointMsgs develop option only shows a couple of not very useful things that are also shown with -Xlog:os. Also remove unused functions.

runtime/safepointMechanism.cpp: log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page));
runtime/sharedRuntime.cpp: log_debug(safepoint)("... found polling page %s exception at pc = "

The debug safepoints() function shows information that is already shown if you call threads() and information that's already in the thread dumps.