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

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

@@ -0,0 +1,14 @@
+package o
+
+class A {
+    <!INAPPLICABLE_INFIX_MODIFIER!>infix fun foo(b: B) = b<!>
+}
+
+class B {
+    fun bar() {}
+}
+
+fun test(a: A, b: B?) {
+    a foo b!!
+    b.bar()
+}