count() to merge with filterNotNull and filterIsInstance + changed test for KT-14191 to use sum()

idea/testData/intentions/loopToCallChain/count/countSomethingAndNotNull.kt

@@ -0,0 +1,14 @@
+// WITH_RUNTIME
+// INTENTION_TEXT: "Replace with 'count{}'"
+// IS_APPLICABLE_2: false
+fun f(list: List<Any?>): Int{
+    var c = 0
+    <caret>for (d in list) {
+        if (d == "") continue
+        if (d != null) {
+            if (d is Int) continue
+            c++
+        }
+    }
+    return c
+}