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

compiler/testData/diagnostics/tests/smartCasts/variables/inPropertySam.fir.kt

@@ -0,0 +1,18 @@
+// FILE: My.java
+
+public interface My {
+    String foo(String arg);
+}
+
+// FILE: test.kt
+
+class Your {
+    val x = My() {
+        arg: String? ->
+        var y = arg
+        val z: String
+        if (y != null) z = y
+        else z = "42"
+        z
+    }
+}