>>> Well, searching for the regexp "defun .*org-babel-execute:" would have 
>>> done that, right?
>>
>> In this specific case, yes.  But in general?
>
> I hope that in a more general case we could use something similar, since 
> every definition of a function should start from "defun " followed by 
> some part of its name, right?
>

Not always, I can imagine functions defined with fset for example.

What about the attached patch?  It seems to work well.