Patch to update libtool in GCC and Src trees

[Steve Ellcey]

> I am the maintainer of newlib.  It's been so long, but IIRC, newlib had 
> its own copy because we had to make a slight change at the time though I 
> don't remember what.
>
> -- Jeff J.

Looking at libtool.m4, it looks like the only difference between the
libtool version and the standard version was in setting
lt_cv_deplibs_check_method.  The orignal libtool.m4 has a case statement
for "linux-gnu*" and the libtool one changed it to be
"linux-gnu*|linux-newlib*".

The latest libtool just checks "linux*" so this local libtool.m4 change
shouldn't be needed if newlib uses the latest libtool.

Steve Ellcey
sje@cup.hp.com