x?.y != null and x?.call() != null provoke now x != null, a set of tests #KT-2127 Fixed

compiler/testData/diagnostics/tests/regressions/Jet72.kt

@@ -11,7 +11,8 @@ val items: ArrayList<Item> = ArrayList<Item>()
 fun test(room : <!PLATFORM_CLASS_MAPPED_TO_KOTLIN!>Object<!>) {
   for(item: Item? in items) {
     if (item?.room === room) {
-      System.out.println("You see " + item?.name)
+      // item?.room is not null
+      System.out.println("You see " + item<!UNNECESSARY_SAFE_CALL!>?.<!>name)
     }
   }
 }