* cygheap.cc (cygheap_init): Set Cygwin default locale values.

* cygheap.h (struct cygheap_locale): New structure.
	(struct user_heap_info): Add cygheap_locale member locale.
	* dcrt0.cc (dll_crt0_1): Revert to calling _setlocale_r so that only
	the applications locale is reverted to "C".
	* environ.cc (environ_init): Remove unused got_lc variable.
	* fhandler.h (class dev_console): Remove now unsed locale variables.
	* fhandler_console.cc (fhandler_console::get_tty_stuff): Remove
	setting dev_console's locale members.
	(dev_console::con_to_str): Use internal locale settings.  Default to
	__ascii_wctomb if charset is "ASCII".
	(fhandler_console::write_normal): Ditto.
	* strfuncs.cc (__ascii_wctomb): Drop declaration.
	(__db_wctomb): Use fixed value 2 instead of not
	necessarily matching MB_CUR_MAX.
	(__eucjp_wctomb): Use 3 instead of MB_CUR_MAX.
	(sys_cp_wcstombs): Remove special case for "C" locale.
	(sys_wcstombs): Implement here.  Use internal locale data stored on
	cygheap.
	(sys_cp_mbstowcs): Remove special case for "C" locale.
	(sys_mbstowcs): Implement here.  Use internal locale data stored on
	cygheap.
	* syscalls.cc (internal_setlocale): New function to set cygheap locale
	data and to reset CWD posix path.
	(setlocale): Just call internal_setlocale from here if necessary.
	* wchar.h (__ascii_wctomb): Declare.
	(sys_wcstombs): Don't define inline, just declare.
	(sys_mbstowcs): Ditto.

winsup/cygwin/fhandler.h

@@ -894,10 +894,6 @@ class dev_console
   bool use_mouse;
   bool raw_win32_keyboard_mode;
 
-  mbtowc_p con_mbtowc;
-  wctomb_p con_wctomb;
-  char con_charset[ENCODING_LEN + 1];
-
   inline UINT get_console_cp ();
   DWORD con_to_str (char *d, int dlen, WCHAR w);
   DWORD str_to_con (mbtowc_p, char *, PWCHAR d, const char *s, DWORD sz);