problem with recent cplus-dem.o gcc/Makefile changes

[David S. Miller]

The following change causes cplus-dem.o to not get built in the gcc
build subdirectory:

	* Makefile.in (cplus-dep.o): Use cplus-dem.c from libiberty.
	* cplus-dem.c: Delete.

I can't figure out why make refuses to built it, even with debugging
turned on make says:

 Finished dependencies of target file `cplus-dem.o'.
Must remake target `cplus-dem.o'.
Successfully remade target file `cplus-dem.o'.
make: Nothing to be done for `cplus-dem.o'.

It never runs the build of cplus-dem.o, I even straced make and saw
that it found ../libiberty/cplus-dem.c and that gcc/cplus-dem.o did
not exist, funny.

I also noted that cp/Make-lang.in does things in a different way, by
sym-linking cplus-dem.c from libiberty into the build area, then
running the compilation by hand, like so:

cxxmain.o: $(srcdir)/../libiberty/cplus-dem.c demangle.h
	rm -f cxxmain.c
	$(LN_S) $(srcdir)/../libiberty/cplus-dem.c cxxmain.c
	$(CC) -c -DMAIN $(ALL_CFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
	  -DVERSION=\"$(version)\" cxxmain.c

So maybe it needs to be done this way?  (I just checked, and this does
make it work)

Later,
David S. Miller
davem@dm.cobaltmicro.com