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

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

@@ -0,0 +1,7 @@
+package aaa
+
+fun bar(a: Int, b: Int) {}
+
+fun foo(a: Int?) {
+    bar(a!!, a)
+}