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/diagnostics/testsWithStdLib/callableReference/function/differentPackageClass.kt

@@ -0,0 +1,25 @@
+// FILE: a.kt
+
+package first
+
+class A {
+    fun foo() {}
+    fun bar(<!UNUSED_PARAMETER!>x<!>: Int) {}
+    fun baz() = "OK"
+}
+
+// FILE: b.kt
+
+package other
+
+import first.A
+
+fun main() {
+    val x = first.A::foo
+    val y = first.A::bar
+    val z = A::baz
+
+    x : KMemberFunction0<A, Unit>
+    y : KMemberFunction1<A, Int, Unit>
+    z : KMemberFunction0<A, String>
+}