[FIR-TEST] Add new testdata generated after changes in previous commit

compiler/testData/diagnostics/tests/dataFlowInfoTraversal/ForLoopRange.fir.kt

@@ -0,0 +1,8 @@
+// !CHECK_TYPE
+
+fun foo(arr: Array<Int>?) {
+    for (x in arr!!) {
+        checkSubtype<Array<Int>>(arr)
+    }
+    checkSubtype<Array<Int>>(arr)
+}