Merged CVS repository of gcc and old-gcc

[Ian Lance Taylor <ian@airs.com>]

In preparation for the future transition to subversion, I've written
some code to merge the old-gcc repository into current mainline.  I
would like to see this merged repository used as the basis for the
conversion to subversion.  The advantage is that it provides revision
history back to 1992, when the gcc sources were first put into a
source code control system.  (At the time, it was RCS.  Before 1992
the source code control system was emacs numbered backup files.)

Since I just wrote this code, I'd like any feedback that people care
to give on the correctness and usability of the generated repository.
People with SSH access to sourceware should be able to access the
temporary merged repository by doing
    cvs -d :ext:gcc.gnu.org:/pool/ian/repo co gcc

This is a snapshot, and it will not be updated to keep up with
mainline changes, except to test bug fixes.  It only includes the gcc
subdirectory, since that is all that is present in old-gcc.  It does
not include some subdirectories which are not present in old-gcc, such
as ada, fortran, java, and testsuite.

Some implementation notes.  I first created a new repository in
/pool/ian/repo, and copied the gcc files there:
    cp -pr /cvs/gcc/gcc/gcc /pool/ian/repo/
Then I ran this command:
    (cd /cvs/gcc/old-gcc; find . -name '*,v' -print) | while read f; do echo $f; /home/ian/gccmerge/objdir/src/cvs -d /pool/ian/repo gccmerge /cvs/gcc/old-gcc gcc $f; done

That command took about 10 minutes to run.  It directly modifies the
file in the repository provided as the -d option.  Yes, for those
scoring at home, this is a modification of CVS itself.  I did it that
way to make easy use of the RCS library within CVS.  Sources are on
gcc-mergebranch of coolo-cvs in /cvs/sourceware.

By the way, in case anybody asks, I will not be doing this merge
before the subversion conversion, because it changes all the CVS
revision numbers and thus breaks all existing working directories.

Thanks.

Ian