[Ecls-list] refactor src/aclocal.m4

[Gabriel Dos Reis]

Juan Jose Garcia-Ripoll <juanjose.garciaripoll at googlemail.com> writes:

| Hi Gabriel,
| 
| thanks a lot for the refactoring. I wrote those tests at a time when I
| was not sure that they existed and did the proper job. BTW, regarding
| your previous question about stdint.h, some platforms define that
| header but they do not provide any or all useful integer types. Thus
| checking for its existence is not enough (old Solaris, for instance).

yes, I remembered the solaris case.  The standard Autoconf tests for the
sized integer types do actually this:
   1. they test for the existence of the headers.
   2. next, they test that the typedefs are actually there.
   3. If 2 fails, then they try to guess the types by running a 
      program similar to yours, except that they avoid possible
      (mis)-optimization by compilers that assume that signed integer
      overflow is undefined-behaviour.

I did not include the diff for 'configure' because I assumed that you
would recreate it yourself.  The other thing I was unsure about was
whetehr you wanted to bump the required (developer) Autotools to version
2.62.

-- Gaby