Small buglet related to autogeneration of limits

[Benjamin Kosnik]

> When trying to build libstdc++-2.90.7 on a Linux system where the default
> compiler installed is g++ version 2.7.xx, and a GCC 2.9.2 is under
> /mypath/gcc, like this:
> 
>     mkdir objdir
>     cd objdir
>     CXX=/mypath/c++ CC=/mypath/gcc ../libstdc++-2.90.7/configure ...

Hmmm. Since 2.90.7, there have been a number of changes to the configure
system. One of them checks to make sure that g++ is of sufficient vintage
to actually compile the library.

I believe GCPPLIB_CHECK_COMPILER in the CVS acinclude.m4 takes care of
this part of your problem...

> The mkcheck script has a hardcoded path to a location where not many
> people will find bash. The second patch changes that to /bin/bash,
> but I realize that there should be a configure check to create that
> line.

Yeah, this was a bummer. The current solution is to use this:

#!/usr/bin/env bash

-Benjamin