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/nestedConstructorFromClass.kt

@@ -0,0 +1,14 @@
+class A {
+    class Nested {
+        val o = 111
+        val k = 222
+    }
+    
+    fun result() = (::Nested)().o + (A::Nested)().k
+}
+
+fun box(): String {
+    val result = A().result()
+    if (result != 333) return "Fail $result"
+    return "OK"
+}