[O] make update2 and ob-comint.el bugs

[Charles C. Berry]

Summary: ob-comint.elc compiled with `make update2' fails, but 
ob-comint.elc byte compiled via dired or with `emacs-lisp-byte-compile' 
succeeds.

===

I recently pushed a fix [1] for ob-comint.el or so I thought. See [2] for 
info on the bug.

First, I tested the fix on my own system by eval'ing ob-comint.el and 
running some tests (including `make test' FWIW).

I also byte-compiled the code using `dired-do-byte-compile', loaded that 
and ran more tests. All good.

Then I pushed that commit to master.

When I did `make update2' the compiled fixes did not work. But loading 
`ob-comint.el' works, and compiling via `dired-do-byte-compile' works and 
loading the result also works.

What?!

So I tried to undo the damage with two more commits, but in each case the 
`make update2' step generated code that was buggy.

I see that `make update2' uses `byte-recompile-directory' and indeed 
running that gives a different (larger) ob-comint.elc than does 
`dired-do-byte-compile'. But both eventually use `byte-compile-file', and 
AFAICS the optimization level is the same in both cases. So I am baffled.

Any advice on how to produce code that works when compiled with `make 
update2' or just to understand what gives here is appreciated.

Best,

Chuck

[1] commit e42454088ff1176cce9cc65a4bd1c6f17fe958ec
[2]<http://permalink.gmane.org/gmane.emacs.orgmode/106557>