current_source_line static.
(list_command): Moved to cli/cli-cmds.c.
(ambiguous_line_spec): Moved to cli/cli-cmds.c.
(get_first_line_listed): New accessor function.
(get_lines_to_list): New accessor function.
(get_current_source_symtab_and_line): New function. Retrieves the
position in the source code that we consider current.
(get_current_or_default_source_symtab_and_line): New function.
Like the above but attempts to determine a default position if one
is not currently defined.
(set_current_source_symtab_and_line): New function. Sets the source
code position considered current and returns the previously set one.
(clear_current_source_symtab_and_line): Reset stored information about
a current source line.
(_initialize_source): Remove registration for the "list" command and
its alias.
* source.h: Add declarations for the new functions above.
* symtab.h: Remove declarations for the global variables mentioned
above.
* breakpoint.c (parse_breakpoint_sals): Use accessor functions to
obtain current source line.
* linespec.c (decode_line_1): Ditto.
* macroscope.c (default_macro_scope): Ditto.
* scm-lang.c (scm_unpac): Ditto.
* stack.c (print_frame_info_base): Ditto.
* symfile.c (clear_symtab_users): Ditto.
* symtab.c (decode_line_spec): Ditto.
* cli/cli-cmds.c (list_command): Moved here from source.c.
(ambiguous_line_spec): Moved here from source.c.
(_init_cli_cmds): Add definition for "list" and its alias.
* Makefile.in: Update dependencies.
