re PR c++/24009 (C++ fails to print #include stack)
PR c++/24009
* input.h (restore_input_file_stack): Declare.
(INPUT_FILE_STACK_BITS): Define.
* toplev.c (fs_p, input_file_stack_history,
input_file_stack_restored, restore_input_file_stack): New.
(push_srcloc, pop_srcloc): Check for input_file_stack_tick
overflowing INPUT_FILE_STACK_BITS bits. Save new state of stack.
(pop_srcloc): Don't free old state of stack.
cp:
* parser.c (struct cp_token): Add input_file_stack_index.
(eof_token): Update.
(cp_lexer_get_preprocessor_token): Save input_file_stack_tick.
(cp_lexer_set_source_position_from_token): Restore input file
stack.
From-SVN: r116479