Fixed ugly bug in nested function support

regression/orig/test069.log

@@ -0,0 +1 @@
+> 0

regression/orig/test070.log

@@ -0,0 +1 @@
+> 0

regression/test069.expr

@@ -0,0 +1,11 @@
+fun f (x) {
+  fun inner (y) {
+    return if y == 0 then 0 else inner (y-1) fi
+  }
+
+  return inner (x)
+}
+
+local n = read ();
+
+write (f (5))

regression/test069.input

@@ -0,0 +1 @@
+5

regression/test070.expr

@@ -0,0 +1,15 @@
+fun f (x) {
+  fun inner1 (y) {
+    return if y == 0 then 0 else inner2 (y-1) fi
+  }
+  
+  fun inner2 (y) {
+    return if y == 0 then 0 else inner1 (y-1) fi
+  }  
+
+  return inner1 (x)
+}
+
+local n = read ();
+
+write (f (5))

regression/test070.input

@@ -0,0 +1 @@
+5