Fix local_cons etc. to not exhaust the stack when in a loop.

Fix local_cons etc. to not exhaust the stack when in a loop.

Problem reported in:
http://lists.gnu.org/archive/html/emacs-devel/2014-09/msg00696.html
* buffer.c (Fother_buffer, other_buffer_safely, init_buffer):
* charset.c (load_charset_map_from_file, Ffind_charset_region)
(Ffind_charset_string):
* chartab.c (uniprop_encode_value_numeric, uniprop_table):
* data.c (wrong_range):
* editfns.c (Fpropertize, format2):
* emacs.c (init_cmdargs, decode_env_path):
* fileio.c (auto_save_error):
* fns.c (Fyes_or_no_p):
* font.c (font_style_to_value, font_parse_xlfd)
(font_parse_family_registry, font_delete_unmatched)
(font_add_log):
* fontset.c (Fset_fontset_font):
* frame.c (x_get_arg):
* keyboard.c (echo_dash, safe_run_hooks_error, parse_menu_item)
(read_char_minibuf_menu_prompt):
* keymap.c (silly_event_symbol_error, describe_vector):
* lread.c (load_warn_old_style_backquotes):
* menu.c (single_menu_item):
* minibuf.c (Fread_buffer):
* process.c (status_message, Fformat_network_address)
(server_accept_connection):
* textprop.c (copy_text_properties):
* xdisp.c (Fcurrent_bidi_paragraph_direction):
* xfns.c (x_default_scroll_bar_color_parameter):
* xfont.c (xfont_open):
* xselect.c (x_clipboard_manager_error_1):
* xterm.c (x_term_init):
Put USE_LOCAL_ALLOCA at the start of the function.
* fns.c (maybe_resize_hash_table): Use build_string instead of
build_local_string, since we'd otherwise need a conditional
USE_LOCAL_ALLOCA here, but this is just debugging output and is
not worth the bother of optimization.
* font.c (font_delete_unmatched): Remove by-hand code that
observed MAX_ALLOCA limit, since it's now done automatically.
* keymap.c (Fsingle_key_description): Put USE_SAFE_ALLOCA at top,
since build_local_string needs its sa_alloc.
* lisp.h (lisp_word_count): New function.
(SAFE_ALLOCA_LISP): Use it.
(USE_LOCAL_ALLOCA): New macro.
(local_cons, make_local_vector, make_local_string):
Observe the MAX_ALLOCA limit.
(LISP_STRING_OVERHEAD): New constant.
(make_local_string): Use it.