Introduce kotlin.jvm.internal.Lambda, superclass for all lambdas

It has its arity precomputed, as opposed to the future KFunctionImpl inheriting
from FunctionImpl, for which the computation of arity can take some time and so
it shouldn't be passed in the constructor and saved as a field

core/reflection.jvm/src/kotlin/reflect/jvm/internal/KFunctionImpl.kt

@@ -21,4 +21,4 @@ import kotlin.jvm.internal.FunctionImpl
 /**
  * @suppress
  */
-public abstract class KFunctionImpl<out R> : FunctionImpl<R>()
+public abstract class KFunctionImpl<out R> : FunctionImpl()