AA FIR: handle smartcasted arg when building call's argument mapping

^KTIJ-25112 Fixed

analysis/analysis-api/testData/components/callResolver/resolveCall/smartCastedNonNullArg.kt

@@ -0,0 +1,8 @@
+private fun test(s: String?) {
+    if (s != null) {
+        <expr>foo(s)</expr>
+    }
+}
+
+private fun foo(s: String) {
+}