Nodaways, most projects don't commit generated configure scripts to
version control any more, but some notable ones still do, e.g., GCC and
the GNU toolchain. The Libtool macros provide a bit of a stumbling
block for this as they are the most prominent remaining cause for
conflicts in merging different changes in those scripts, due to the use
of expanded line numbers in the form of the __oline__ autom4te feature.
Now, since most modern shells (except for dash, hello, Debian :-)
implement $LINENO support fairly well, I think there is little reason
to rely on this arcane way of expanding line numbers at configure script
generation time any more. I thus propose this patch to remove them.