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

compiler/testData/diagnostics/tests/smartCasts/castchecks/insideCall.fir.kt

@@ -0,0 +1,13 @@
+// !LANGUAGE: +SafeCastCheckBoundSmartCasts
+// See KT-19007
+
+// Stub
+fun String.indexOf(arg: String) = this.length - arg.length
+
+// Stub
+fun String.toLowerCase() = this
+
+fun foo(a: Any) {
+    // Should compile in 1.2
+    (a as? String)?.indexOf(a.toLowerCase())
+}