add test for issue #1504

test/val/bug1504.c

@@ -0,0 +1,13 @@
+
+/* bug #1504 - Some compilation failures */
+
+#include <stdio.h>
+
+int main(void)
+{
+    int i = 0, *p = &i;
+    switch (i) case 0: case 1: i = 21;  /* Should be OK but fails */
+    p++[0] += 21;                       /* Should be OK but fails */
+    printf("%d\n", i);
+    return i != 42;
+}