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

compiler/testData/diagnostics/tests/smartCasts/ifExprInConditionNonNull.fir.kt

@@ -0,0 +1,11 @@
+fun baz(s: String?, b: Boolean?): String {
+    val t = if (if (b == null) return "" else b) {
+        if (s == null) return ""
+        s
+    }
+    else {
+        if (s != null) return s
+        ""
+    }
+    return t
+}