Fix uninitialized register read problem.
* builtins.c (expand_builtin_return_addr): Set
current_function_accesses_prior_frames when count != 0. Use
frame_pointer_rtx when count == 0.
* function.h (struct function): Add accesses_prior_frames field.
(current_function_accesses_prior_frames): Define.
* reload1.c (init_elim_table): Check
current_function_accesses_prior_frames.
* doc/tm.texi (INITIAL_FRAME_ADDRESS_RTX): Update docs.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@103294
138bc75d-0d04-0410-961f-
82ee72b054a4