The trampoline now properly restores the link register as well as the stack
pointer. As a minor optimisation, now only callee-saved registers are
restored: the scratch registers don't need that.

2018-05-22  Jerome Lambourg  <lambourg@adacore.com>

gcc/ada/

	* sigtramp-qnx.c: Properly restore link register in signal trampoline.

From-SVN: r260530