This patch adds varobj support for Ada variables. Most of the code
is implemented in a separate Ada-specific file called ada-varobj.c.
The only bits in varobj.c are the functions used as the hooks in
the language-specific varobj's vector.
gdb/ChangeLog:
* ada-varobj.h, ada-varobj.c: New files.
* Makefile.in (SFILES): Add ada-varobj.c.
(HFILES_NO_SRCDIR): Add ada-varobj.h.
(COMMON_OBS): Add ada-varobj.o.
