tui_expand_tabs only has a single caller. This patch removes this
function, in favor of a tab-expanding variant of string_file. This
simplifies the code somewhat.
gdb/ChangeLog
2020-07-01 Tom Tromey <tom@tromey.com>
* tui/tui-regs.h (struct tui_data_item_window) <content>: Now a
std::string.
* tui/tui-regs.c (class tab_expansion_file): New.
(tab_expansion_file::write): New method.
(tui_register_format): Change return type. Use
tab_expansion_file.
(tui_get_register, tui_data_window::display_registers_from)
(tui_data_item_window::rerender): Update.
* tui/tui-io.h (tui_expand_tabs): Don't declare.
* tui/tui-io.c (tui_expand_tabs): Remove.
7a02bab704