PSI2IR KT-49526 function reference type approximation hack

compiler/testData/codegen/box/callableReference/kt49526a.kt

@@ -0,0 +1,20 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+// FIR_STATUS: callable reference type approximation hack not implemented
+
+fun <T> id(x: T): T = x
+
+fun <T> intersect(x: T, y: T): T = x
+
+interface I1
+interface I2
+
+class C1 : I1, I2 {
+    override fun toString() = "OK"
+}
+
+class C2 : I1, I2
+
+fun box() =
+    intersect(C1(), C2())
+        .let(::id)
+        .toString()