extraclean and admin/grammars [was Re: Git master head build failure?]

[Glenn Morris]

Eli Zaretskii wrote:

> "make bootstrap" isn't for building from a pristine tree, that's not
> its purpose.

I consider that to be the purpose of bootstrap.
I disagree with the description of extraclean as "and all generated files".

Emacs use of extraclean is really an abuse - see comments in the
top-level Makefile. IIRC, the only differences between extraclean
and bootstrap-clean are:

1) bootstrap-clean does not delete the generated leim files.
This is because they are slow to rebuild and the sources rarely change.

2) bootstrap-clean does not delete the generated semantic grammars.
These are not slow to rebuild. As my comment in admin/grammars/Makefile.in
says, these could easily be deleted in bootstrap-clean.
I don't even really remember why I did it that way now.

Since several people seem to have an issue lately with these files
getting corrupted, I have a good mind to make that change.