Test a for() loop as well.

tests/loop_for_test.exp

@@ -0,0 +1,51 @@
+Hello variables: 0 0 2
+Hello variables: 0 1 2
+Hello variables: 0 3 2
+Hello variables: 0 4 2
+Hello variables: 0 5 2
+Hello variables: 1 0 2
+Hello variables: 1 1 2
+Hello variables: 1 3 2
+Hello variables: 1 4 2
+Hello variables: 1 5 2
+Hello variables: 2 0 2
+Hello variables: 2 1 2
+Hello variables: 2 3 2
+Hello variables: 2 4 2
+Hello variables: 2 5 2
+Hello variables: 3 0 2
+Hello variables: 3 1 2
+Hello variables: 3 3 2
+Hello variables: 3 4 2
+Hello variables: 3 5 2
+Hello variables: 4 0 2
+Hello variables: 4 1 2
+Hello variables: 4 3 2
+Hello variables: 4 4 2
+Hello variables: 4 5 2
+Hello variables: 5 0 2
+Hello variables: 5 1 2
+Hello variables: 5 3 2
+Hello variables: 5 4 2
+Hello variables: 5 5 2
+Hello variables: 6 0 2
+Hello variables: 6 1 2
+Hello variables: 6 3 2
+Hello variables: 6 4 2
+Hello variables: 6 5 2
+Hello variables: 7 0 2
+Hello variables: 7 1 2
+Hello variables: 7 3 2
+Hello variables: 7 4 2
+Hello variables: 7 5 2
+Hello variables: 8 0 2
+Hello variables: 8 1 2
+Hello variables: 8 3 2
+Hello variables: 8 4 2
+Hello variables: 8 5 2
+Hello variables: 9 0 2
+Hello variables: 9 1 2
+Hello variables: 9 3 2
+Hello variables: 9 4 2
+Hello variables: 9 5 2
+Variable $c: 4