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

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

@@ -0,0 +1,11 @@
+public fun foo(x: String?, y: String?): Int {
+    while (true) {
+        val z = (if (y == null) break else x) ?: y
+        // z is not null in both branches
+        z.length
+        // y is not null in both branches
+        y.length
+    }
+    // y is null because of the break
+    return y.<!INAPPLICABLE_CANDIDATE!>length<!>
+}