JVM_IR: Fix Inline CallableReferences with Varargs

- Added tests to demonstrate broken behaviour: the interaction of inline
  functions and callable references with varargs and defaults in various
  combinations.
- Refactored InlineCallableReferencesToLambdaPhase to look like and use
  some of the infrastructure from CallableReferenceLowering.
- Lifted some of this infrastructure out to be broadly reusable.

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

@@ -0,0 +1,11 @@
+// !LANGUAGE: +NewInference +FunctionReferenceWithDefaultValueAsOtherType
+// WITH_RUNTIME
+// IGNORE_BACKEND: JS_IR
+
+inline fun foo(mkString: () -> String): String =
+        mkString()
+
+fun bar (xs: CharArray = charArrayOf('O','K')) =
+        String(xs)
+
+fun box(): String = foo(::bar)