Update spill LAP machinery and compile anonymous lambdas
* lisp/emacs-lisp/comp.el (comp-spill-lap-function): Make use of
byte-to-native-lambdas-h and update for 'byte-to-native-func-def'.
(comp-spill-lap-function): Rework logic to retrive LAP using
'byte-to-native-lambdas-h'.
(comp-emit-for-top-level): Update for 'byte-to-native-function'.
* lisp/emacs-lisp/bytecomp.el: Add commentary on new spill LAP
mechanism.
(byte-to-native-lambda, byte-to-native-func-def): New structures.
(byte-to-native-top-level): Indent.
(byte-to-native-lambdas-h): Update doc.
(byte-compile-lapcode): Add a 'byte-to-native-lambda' instance
into byte-to-native-lambdas-h instead of just LAP.
(byte-compile-file-form-defmumble): Store into
'byte-to-native-func-def' only the byte compiled function, the LAP
will be retrived through 'byte-to-native-lambdas-h'.
(byte-compile-lambda): Return the byte compiled function.