[gdb/testsuite] Add gdb.tui/reread.exp

Add a regression test for commit d68f983f88c ("Fix heap-use-after-free because
all_objfiles_removed triggers tui_display_main").

When building with address sanitizer, and reverting the commit it triggers the
heap-use-after-free.

Tested on aarch64-linux.

PR symtab/31697
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31697