RFR(XS) 8050167: linux-sparcv9: hs_err file does not show any stack information

[Zhengyu Gu]

This is a small fix to setup the first stack frame from exception 
handler. Sparc's sigcontext does not contain frame pointer, so uses 
frame::unpatchable instead.


Bug: https://bugs.openjdk.java.net/browse/JDK-8050167
Webrev: http://cr.openjdk.java.net/~zgu/8050167/webrev.00/


Thanks,

-Zhengyu