Support default arguments and varargs for callable references

#KT-8834
 #KT-19869
 #KT-25514

compiler/testData/codegen/box/callableReference/varargAndDefaults/simpleDefaultArgument.kt

@@ -0,0 +1,10 @@
+// !LANGUAGE: +NewInference
+// IGNORE_BACKEND: JS_IR, JVM_IR
+
+fun foo(x: String, y: String = "K"): String = x + y
+
+fun call(f: (String) -> String, x: String): String = f(x)
+
+fun box(): String {
+    return call(::foo, "O")
+}