Fix more nocode_wanted jump problems

In statement expression we really mustn't emit backward jumps
under nocode_wanted (they will form infinte loops as no expressions
are evaluated).  Do-while and explicit loop with gotos weren't
handled.

tests/tests2/82_nocode_wanted.c

@@ -27,6 +27,36 @@ static void kb_wait_2(void)
         timeout--;
     } while (timeout);
 }
+static void kb_wait_2_1(void)
+{
+    unsigned long timeout = 2;
+    do {
+        (1 ? 
+            printf("timeout=%ld\n", timeout) :
+            ({
+                do {
+                    printf("error\n");
+		} while (1);
+            })
+        );
+        timeout--;
+    } while (timeout);
+}
+static void kb_wait_2_2(void)
+{
+    unsigned long timeout = 2;
+    do {
+        (1 ? 
+            printf("timeout=%ld\n", timeout) :
+            ({
+                label:
+                    printf("error\n");
+		goto label;
+            })
+        );
+        timeout--;
+    } while (timeout);
+}
 static void kb_wait_3(void)
 {
     unsigned long timeout = 2;
@@ -73,6 +103,8 @@ int main()
     printf("begin\n");
     kb_wait_1();
     kb_wait_2();
+    kb_wait_2_1();
+    kb_wait_2_2();
     kb_wait_3();
     kb_wait_4();
     printf("end\n");

tests/tests2/82_nocode_wanted.expect

@@ -7,4 +7,8 @@ timeout=2
 timeout=1
 timeout=2
 timeout=1
+timeout=2
+timeout=1
+timeout=2
+timeout=1
 end