added repro cases from #2172 as tests

test/todo/bug2172_invalid_code.c

@@ -0,0 +1,56 @@
+
+// bug #2172 - Invalid code generated for switch statement
+
+#include <stdlib.h>
+#include <stdio.h>
+
+// cc65 -o bug2172.s -Cl -Oirs -T -t c64 bug2172.c
+int func(int expr)
+{
+    switch (expr) {
+        int i;
+        case 0:
+            i = 17;
+            return i;
+        default:
+            i = 16;
+            return i;
+    }
+}
+
+int err = 0;
+
+int main(void)
+{
+    int i = 0;
+    int n = 42;
+    for (i = -3; i < 0; i++) {
+        n = func(i);
+        if ((i < -3) || (i >= 0)) {
+            goto stackerr;
+        }
+        printf("i:%d expect:16 got:%d\n", i, n);
+        if (n != 16) {
+            err++;
+        }
+    }
+    n = func(0);
+    printf("i:%d expect:17 got:%d\n", 0, n);
+    if (n != 17) {
+        err++;
+    }
+    for (i = 1; i < 4; i++) {
+        n = func(i);
+        if ((i < 1) || (i >= 4)) {
+            goto stackerr;
+        }
+        printf("i:%d expect:16 got:%d\n", i, n);
+        if (n != 16) {
+            err++;
+        }
+    }
+    return err;
+stackerr:
+    fputs("stack messed up?\n", stdout);
+    return -1;
+}

test/todo/bug2172b_invalid_code.c

@@ -0,0 +1,51 @@
+
+#include <stdlib.h>
+#include <stdio.h>
+
+/* Just some arbitrary code, more fun with goto */
+int func(int m)
+{
+    long x = -42;               /* sp: -4 */
+    switch (x) {
+        /* return 0; // C99 only */
+        int i = 42;             /* sp: -6 */
+L0:
+        --i;
+default:
+        if (i != 0) {
+            long j = 13;        /* sp: -10 */
+            goto L1;
+L1:
+case 0x7FFF01:
+            m--;
+case 0x7EFF0001:
+case 0x7FFF0001:
+            i++;
+        }                       /* sp: -6 */
+case 0x7FFF00:
+case 0x7FFF0000:
+        break;
+        goto L0;
+        {
+            int skipped = 42;   /* sp: -8 */
+case 0x7EFF00:
+case 0x7EFF0000:
+            ++skipped;
+        }                       /* sp: -6 */
+    }                           /* sp: -4 */
+
+    return m;
+}
+
+int err = 0;
+
+int main(void)
+{
+    int n = 42;
+    n = func(7);
+    if (n != 7) {
+        err++;
+    }
+    printf("n:%d\n", n);
+    return err;
+}