(gdb-var-create-handler, gdb-var-delete)

(gdb-var-create-handler, gdb-var-delete)
(gdb-edit-value, gdb-speedbar-expand-node)
(gdb-get-create-buffer,  gdb-breakpoints-mode)
(gdb-toggle-breakpoint, gdb-delete-breakpoint)
(gdb-goto-breakpoint, gdb-frames-mode, gdb-registers-mode)
(gdb-locals-mode, gdb-find-file-hook): Use buffer-local-value.
(gdb-send-item, ): Use buffer-local-value and simplify.