intl: Merge from glibc

intl: Merge from glibc

* bindtextdom.c: Update copyright to use year ranges.
* dcgettext.c: Update copyright to use year ranges.
[_LIBC]: Use libc_hidden_def instead of INTDEF.
* dcigettext.c: Update copyright to use year ranges.
Test HAVE_TSEARCH with #ifdef rather than #if.
(DCIGETTEXT) [_LIBC]: Use __current_locale_name instead of
_current_locale_name.
* dcngettext.c: Update copyright to use year ranges.
* dgettext.c: Update copyright to use year ranges.
[_LIBC]: Remove use of INTUSE macro.
* dngettext.c: Update copyright to use year ranges.
* explodename.c: Likewise.
* finddomain.c: Update copyright to use year ranges.
(_nl_finddomain_subfreeres): Use void in no-arguments function
definition.
* gettext.c: Update copyright to use year ranges.
[_LIBC]: Remove use of INTUSE macro.
* gettextP.h: Update copyright to use year ranges.
[_LIBC]: Forward declaration of struct loaded_domain.
* gmo.h: Update copyright to use year ranges.
* hash-string.c: Likewise.
* hash-string.h: Likewise.
* l10nflist.c: Update copyright to use year ranges.
[_LIBC]: Remove use of INTUSE macro.
Wrap pop function in [!ARCH_POP].
* loadinfo.h: Update copyright to use year ranges.
* loadmsgcat.c: Likewise.
* localealias.c: Update copyright to use year ranges.
Test ENABLE_RELOCATABLE with #ifdef rather than #if.
[_LIBC]: Use __strcasecmp_l for strcasecmp.
[_LIBC]: Use __fgets_unlocked for FGETS.
Test HAVE_DECL_FGETS_UNLOCKED with #ifdef rather than #if.
Test HAVE_DECL_FEOF_UNLOCKED with #ifdef rather than #if.
(read_alias_file) [_LIBC]: Open file with O_CLOEXEC.
(extend_alias_table): Use void in no-arguments function
definition.
* ngettext.c: Update copyright to use year ranges.
* plural-exp.c: Update copyright to use year ranges.
Test __APPLE_CC__ with #ifdef rather than #if.
(GERMANIC_PLURAL): Make const.
(init_germanic_plural): Use void in no-arguments function
definition.
* plural-exp.h: Update copyright to use year ranges.
(GERMANIC_PLURAL): Make const.
* plural.y: Update copyright to use year ranges.
* textdomain.c: Likewise.