Don't create KClass and KPackage instances in <clinit>

This proved to be a fragile technique, which probably doesn't even improve
performance in most cases but has lots of unexpected problems: unconditional
initialization of reflection classes, increasing the size of the bytecode, bugs
with <clinit> in annotations on JVM 6, inability to support conversion of a
class from Kotlin to Java without recompiling clients which use it
reflectively, etc.

compiler/testData/codegen/boxWithStdlib/reflection/mapping/syntheticFields.kt

@@ -1,7 +1,7 @@
 import kotlin.reflect.jvm.kotlin
 
-class A {
-    // There's a synthetic "$kotlinClass" field here
+enum class A {
+    // There's a synthetic field "$VALUES" here
 }
 
 fun box(): String {