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/toString.kt

@@ -0,0 +1,23 @@
+fun foo(s: String) {}
+
+class A {
+    fun bar(): String = ""
+}
+
+fun A.baz() {}
+
+
+fun box(): String {
+    val f = "${::foo}"
+    if (f != "kotlin.reflect.KFunctionImpl1<java.lang.String, kotlin.Unit>") return "Fail foo: $f"
+
+    val nameOfA = (A() as java.lang.Object).getClass().getName()
+
+    val g = "${A::bar}"
+    if (g != "kotlin.reflect.KMemberFunctionImpl0<$nameOfA, java.lang.String>") return "Fail bar: $g"
+
+    val h = "${A::baz}"
+    if (h != "kotlin.reflect.KExtensionFunctionImpl0<$nameOfA, kotlin.Unit>") return "Fail baz: $h"
+
+    return "OK"
+}