JVM_IR KT-45103 optimize direct invoke for lambdas and callable refs

compiler/testData/codegen/box/closures/kt4106.kt

@@ -1,8 +1,10 @@
+fun <T> eval(fn: () -> T) = fn()
+
 class Foo(private val s: String) {
     inner class Inner {
-        private val x = {
+        private val x = eval {
             this@Foo.s
-        }()
+        }
     }
 
     val f = Inner()