JVM IR: Avoid direct invokes in callable reference tests

Due to the direct invoke optimization, most callable reference tests
were not generating callable references/lambdas.

compiler/testData/codegen/box/callableReference/function/local/extension.kt

@@ -2,5 +2,5 @@ class A
 
 fun box(): String {
     fun A.foo() = "OK"
-    return (A::foo)(A())
+    return (A::foo).let { it(A()) }
 }