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

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

@@ -0,0 +1,8 @@
+// !CHECK_TYPE
+
+fun foo(arr: Array<out Number>): Int {
+    @Suppress("UNCHECKED_CAST")
+    val result = (arr as Array<Int>)[0]
+    checkSubtype<Array<Int>>(arr)
+    return result
+}