Introduce module 'reflection', move KFunctionN to it

Metadata for KFunction classes is now longer serialized along with built-in
classes. This effectively means that it's no longer possible to find KFunction
classes via dependency on built-ins. There should be a kotlin-runtime library
in the specified classpath for reflection types to be resolvable.

A lot of tests were moved and changed, because tests on callable references
require stdlib in classpath from now on

compiler/testData/codegen/boxWithStdlib/callableReference/function/genericMember.kt

@@ -0,0 +1,5 @@
+class A<T>(val t: T) {
+    fun foo(): T = t
+}
+
+fun box() = A("OK").(A<String>::foo)()