bug#33247: makefile mode comment color

[Stefan Monnier <monnier@IRO.UMontreal.CA>]

> Why do we have this setting for makefiles at all?

That's to handle the /bin/sh comments on the command lines of rules,
where the code is run by /bin/sh and hence obeys the corresponding
rules.  E.g.

   foo.o: foo.c
   	echo This is#not a comment
   	$(CC) $(CFLAGS) -o $@ $<  #This is an sh comment

> Are there any such
> restrictions on comments in Makefiles?  Stefan?

Maybe we should conditionalize on the presence of a leading TAB at the
beginning of the line.

BTW, I recently saw that the above is wrong in cases like

   foo.o: foo.c
   	@#An sh comment not recognized by current makefile mode
   	$(CC) $(CFLAGS) -o $@ $<  #This is a comment

so if you can fix both of those while you're there, that'd be great!


-- Stefan