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

compiler/testData/diagnostics/tests/overload/EmptyArgumentListInLambda.fir.kt

@@ -0,0 +1,8 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+fun foo(g: () -> Int) {}
+fun foo(f: (Int) -> Int) {}
+
+fun test() {
+    <!AMBIGUITY!>foo<!> { -> 42 }
+}