bug#16008: semantic/grammar-wy.el cannot be bootstrapped

Stefan Monnier wrote:

> In the mean time I suggest the patch below which I recently sent to
> emacs-devel.

Instead of a -boot version, how about regenerating it but not deleting it:

--- a/admin/grammars/Makefile.in
+++ b/admin/grammars/Makefile.in
@@ -51,16 +51,19 @@ BOVINE = \
 	${bovinedir}/make-by.el \
 	${bovinedir}/scm-by.el
 
-## FIXME Should include this one too:
-##	${cedetdir}/semantic/grammar-wy.el
-## but semantic/grammar.el (which is what we use to generate grammar-wy.el)
-## requires it!  https://debbugs.gnu.org/16008
-WISENT = \
+WISENT1 = \
 	${wisentdir}/javat-wy.el \
 	${wisentdir}/js-wy.el \
 	${wisentdir}/python-wy.el \
 	${cedetdir}/srecode/srt-wy.el
 
+DELETE = ${BOVINE} ${WISENT1}
+
+## The last one is special: semantic/grammar.el (which is what generates it)
+## requires it.  https://debbugs.gnu.org/16008
+## So we generate it, but never delete it.
+WISENT = ${WISENT1} ${cedetdir}/semantic/grammar-wy.el
+
 ALL = ${BOVINE} ${WISENT}
 
 .PHONY: all bovine wisent
@@ -107,7 +110,7 @@ distclean:
 bootstrap-clean:
 
 gen-clean:
-	rm -f ${ALL}
+	rm -f ${DELETE}
 
 maintainer-clean: gen-clean distclean
 

> Glenn, could you arrange to "auto""-update `grm-wy-boot.el` like you do
> for `ldefs-boot.el`?

It's admin/update_autogen.