[rfa/rfc] Build libcommon.a for gdb and gdbserver

[Tom Tromey]

>>>>> "Yao" == Yao Qi <yao@codesourcery.com> writes:

Yao> gdb/
Yao> 	* Makefile.in (configure-common): Remove.  Let Makefile
Yao> 	in dir common to rebuild itself.
Yao> 	(common/Makefile): Likewise.

This part looks ok.
But the code still has:

Yao>  $(LIBCOMMON): $(LIBCOMMON_DIR)/Makefile
Yao>  	@$(MAKE) $(FLAGS_TO_PASS) DO=all DODIRS=common subdir_do
 
Now there isn't a rule to build $(LIBCOMMON_DIR)/Makefile.

I suspect the $(LIBCOMMON) target isn't needed, but removing it may
require some other changes.

Tom