Take control flow into account for checking fall-through switch branches

#KT-16133 Fixed

j2k/testData/fileOrElement/switch/nestedSwitchFallback.java

@@ -0,0 +1,15 @@
+//method
+public String foo(int i, int j) {
+    switch (i) {
+        case 0:
+            switch (j) {
+                case 1:
+                    return "0, 1";
+                case 2:
+                    return "0, 2";
+            }
+        case 1:
+            return "1, x";
+        default:
+            return "x, x";
+}