Implemented function calls

examples/hello/hello.q

@@ -1,8 +1,12 @@
 main() {
+	hello()
+}
+
+hello() {
 	write := 1
 	stdout := 1
-	exit := 60
+	address := 4194305
+	length := 3
 
-	syscall(write, stdout, 4194305, 3)
-	syscall(exit, 0)
+	syscall(write, stdout, address, length)
 }