Codegen for callable reference expressions

#KT-1183 In Progress

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

@@ -0,0 +1,11 @@
+fun foo(o: Int, k: Int) = o + k
+
+class A {
+    fun bar() = (::foo)(111, 222)
+}
+
+fun box(): String {
+    val result = A().bar()
+    if (result != 333) return "Fail $result"
+    return "OK"
+}