Use C-a x to quit qemu in tests. Add usertests

tests/fork.exp

@@ -4,10 +4,9 @@ spawn make run arch=x86_64
 sleep 2
 expect ">>"
 sleep 2
-send "biscuit/fork\n"
+send -- "biscuit/fork\r"
 sleep 2
 expect "hello from 100"
 expect "parent done!"
-sleep 2
+send -- "^Ax"
-send "busybox halt -f\n"
+wait -nowait
-expect ">>"

tests/usertests.exp

@@ -0,0 +1,11 @@
+set timeout -1
+cd ../kernel
+spawn make run arch=x86_64
+sleep 2
+expect ">>"
+sleep 2
+send -- "biscuit/usertests\r"
+sleep 2
+expect "exec test"
+send -- "^Ax"
+wait -nowait

user

@@ -1 +1 @@
-Subproject commit 9ba5207eecc6f3685dd976d1a5aa6f23b5066f0b
+Subproject commit 091b95fae21bf42c8ee403056bda830f65255286