Treat DSE exceptions like DSI exceptions when generating signinfo.

Both can generate SIGSEGV, but DSEs would have put the wrong address
into the siginfo structure when the signal was delivered.

MFC after:	1 week

sys/powerpc/powerpc/exec_machdep.c

@@ -154,7 +154,8 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
 	 * Fill siginfo structure.
 	 */
 	ksi->ksi_info.si_signo = ksi->ksi_signo;
-	ksi->ksi_info.si_addr = (void *)((tf->exc == EXC_DSI) ? 
+	ksi->ksi_info.si_addr =
+	    (void *)((tf->exc == EXC_DSI || tf->exc == EXC_DSE) ? 
 	    tf->dar : tf->srr0);
 
 	#ifdef COMPAT_FREEBSD32