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

compiler/testData/diagnostics/tests/smartCasts/loops/whileTrivial.fir.kt

@@ -0,0 +1,11 @@
+fun x(): Boolean { return true }
+
+public fun foo(p: String?): Int {
+    // Like whileTrue but 2 == 2 is in use
+    while(2 == 2) {
+        p!!.length
+        if (x()) break
+    }
+    // Smart cast should not work in this case, see KT-6284
+    return p.length
+}