toplevel:
* cpplex.c: Don't include sys/mman.h.
(cpp_push_buffer, cpp_pop_buffer): Moved to cpplib.c.
* cpplib.c: Include sys/mman.h and obstack.h.
(cpp_push_buffer): Moved from cpplex.c; allocate buffers on an
obstack.
(cpp_pop_buffer): Moved from cpplex.c; free buffers from an obstack.
(_cpp_unwind_if_stack): Now static, unwind_if_stack. Don't
bother freeing if stack entries (they will be freed with their buffer).
(do_endif): Free if stack entries from the buffer obstack.
(push_conditional): Allocate if stack entries from the buffer obstack.
(find_answer): Rename to _cpp_find_answer.
(do_assert, do_unassert): Update.
* cppinit.c: Don't include hashtab.h or splay-tree.h.
(report_missing_guard): Moved to cppfiles.c.
(cpp_reader_init): Call cpp_init_stacks, cpp_init_macros,
cpp_init_includes.
(cpp_cleanup): Call cpp_cleanup_stacks, cpp_cleanup_macros,
cpp_cleanup_includes. Don't destroy hashtab or
all_include_files here.
(cpp_finish): Use _cpp_report_missing_guards.
* cppfiles.c (report_missing_guard): Moved from cppinit.c.
(_cpp_init_include_table): Rename _cpp_init_includes.
(_cpp_cleanup_includes, _cpp_report_missing_guards): New.
* cppexp.c (parse_assertion): Update for new name of
find_answer.