Added tests

idea/testData/intentions/useWithIndex/indexIncrementTwice.kt

@@ -0,0 +1,11 @@
+// WITH_RUNTIME
+// IS_APPLICABLE: false
+fun foo(list: List<String>): Int? {
+    var index = 0
+    <caret>for (s in list) {
+        val x = s.length * index++
+        index++
+        if (x > 0) return x
+    }
+    return null
+}

idea/testData/intentions/useWithIndex/indexUsedAfterLoop.kt

@@ -0,0 +1,11 @@
+// WITH_RUNTIME
+// IS_APPLICABLE: false
+fun foo(list: List<String>): Int {
+    var index = 0
+    <caret>for (s in list) {
+        val x = s.length * index++
+        print(x)
+        print(s)
+    }
+    return index
+}