sigtramp-vxworks-target.inc: sigtramp-vxworks: force the stack alignment for x86_64.

sigtramp-vxworks-target.inc: sigtramp-vxworks: force the stack alignment for x86_64.

2016-04-18  Jerome Lambourg  <lambourg@adacore.com>

	* sigtramp-vxworks-target.inc: sigtramp-vxworks: force the stack
	alignment for x86_64.
	* init.c: Better fix for guard page reset on x86_64-vx7.
	Do not try to retrieve the page that actually raised
	the signal as the probing mechanism used on x86_64 do not allow
	such retrieval. We thus just test if the guard page is active,
	and re-activate it if not.

From-SVN: r235102