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

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

@@ -0,0 +1,21 @@
+open class Base {
+    fun bar(x: Int): Int = x + 1
+}
+
+class Derived : Base() {
+    fun baz(x: Int): Int = x + 1
+
+    fun foo() {
+        val x: Int? = null
+
+        super.bar(x)
+        this.baz(x)
+        if (x == null) return
+        super.bar(x)
+        this.baz(x)
+
+        val y: Int? = null
+        if (y != null) super.bar(this.baz(y))
+        else this.baz(super.bar(y))
+    }
+}