Add call pseudo instruction

tools/builtin.s

@@ -0,0 +1,29 @@
+.global printi
+.type printi, @function
+
+.text
+printi:
+    addi sp, sp, -8
+    sw s0, 0(sp)
+    sw ra, 4(sp)
+    addi s0, sp, 8
+
+    addi t0, a0, 0
+    addi a0, a0, '0'
+    sw a0, 0(s0)
+    addi a0, x0, 1
+    addi a1, s0, 0
+    addi a2, x0, 1
+    addi a7, x0, 64
+    ecall
+
+    addi t1, x0, '\n'
+    sw t1, 0(s0)
+    ecall
+
+    addi a0, t0, 0
+
+    lw s0, 0(sp)
+    lw ra, 4(sp)
+    addi sp, sp, 8
+    ret

tools/init.c

@@ -118,7 +118,6 @@ enum status run_test(const char *file_entry_name)
         close(pipe_ends[0]);
 
         int wait_status = 0;
-        wait(&wait_status);
 
         make_path(filename, "./expectations/", file_entry_name, ".txt");