RFR (S): 8245509: Crash handler itself crashes when reporting Unsafe.putInt(0) crash

[gerard ziemski]

hi all,

Please review this small and simple fix that adds ResourceMark to crash 
handler when printing register info, without which can trigger fatal 
error if the contents of a register happens to be an oop, which 
uses as_C_string(), that in turn calls ResourceArea::allocate_bytes(), 
which requires a ResourceMark.

If thread is not available, we do not attempt to print anything at this 
step (i.e. print_register_info()), but the very next step (i.e. 
print_context()) will always print the registers as HEX values.

bug link at https://bugs.openjdk.java.net/browse/JDK-8245509
webrev at http://cr.openjdk.java.net/~gziemski/8245509_rev1
passes Mach5 hs_tier1,2,3,4,5


cheers