K 10
svn:author
V 8
vangyzen
K 8
svn:date
V 27
2018-11-30T22:44:33.156439Z
K 7
svn:log
V 380
Fix reporting of SS_ONSTACK

Fix reporting of SS_ONSTACK in nested signal delivery when sigaltstack()
is used on some architectures.

Add a unit test for this.  I tested the test by introducing the bug
on amd64.  I did not test it on other architectures.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D18347

END