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

compiler/testData/diagnostics/tests/inference/regressions/kt731.fir.kt

@@ -0,0 +1,19 @@
+// !WITH_NEW_INFERENCE
+// !CHECK_TYPE
+
+//KT-731 Missing error from type inference
+package a
+
+class A<T>(x: T) {
+    val p = x
+}
+
+fun <T, G> A<T>.foo(x: (T)-> G): G {
+    return x(this.p)
+}
+
+fun main() {
+    val a = A(1)
+    val t: String = a.foo({p -> p})
+    checkSubtype<String>(t)
+}