gdb: make objfile_has_full_symbols and objfile_has_symbols methods of objfile

They seem like good candidates to become methods, just like
objfile::has_partial_symbols.

Change-Id: Ic6df83012629c1137708b8ceb327f9868d8abcb5
Reviewed-By: Guinevere Larsen <guinevere@redhat.com>
5 files changed