Avoid setlocale bugs in tests.

* modules/btowc (Dependencies): Add setlocale.
* modules/c-strcase (Dependencies): Likewise.
* modules/mbmemcasecmp (Dependencies): Likewise.
* modules/mbmemcasecoll (Dependencies): Likewise.
* modules/mbrtowc (Dependencies): Likewise.
* modules/mbscasecmp (Dependencies): Likewise.
* modules/mbscasestr (Dependencies): Likewise.
* modules/mbschr (Dependencies): Likewise.
* modules/mbscspn (Dependencies): Likewise.
* modules/mbsinit (Dependencies): Likewise.
* modules/mbsncasecmp (Dependencies): Likewise.
* modules/mbsnrtowcs (Dependencies): Likewise.
* modules/mbspbrk (Dependencies): Likewise.
* modules/mbspcasecmp (Dependencies): Likewise.
* modules/mbsrchr (Dependencies): Likewise.
* modules/mbsrtowcs (Dependencies): Likewise.
* modules/mbsspn (Dependencies): Likewise.
* modules/mbsstr (Dependencies): Likewise.
* modules/nl_langinfo (Dependencies): Likewise.
* modules/quotearg (Dependencies): Likewise.
* modules/unicase/locale-language (Dependencies): Likewise.
* modules/unicase/ulc-casecmp (Dependencies): Likewise.
* modules/unicase/ulc-casecoll (Dependencies): Likewise.
* modules/unigbrk/ulc-grapheme-breaks (Dependencies): Likewise.
* modules/unistdio/u8-vasnprintf (Dependencies): Likewise.
* modules/unistdio/u16-vasnprintf (Dependencies): Likewise.
* modules/unistdio/u32-vasnprintf (Dependencies): Likewise.
* modules/unistdio/ulc-vasnprintf (Dependencies): Likewise.
* modules/uniwbrk/ulc-wordbreaks (Dependencies): Likewise.
* modules/vasnprintf-posix (Dependencies): Likewise.
* modules/wcrtomb (Dependencies): Likewise.
* modules/wcsnrtombs (Dependencies): Likewise.
* modules/wcsrtombs (Dependencies): Likewise.

modules/mbsrchr-tests

@@ -6,6 +6,7 @@ m4/locale-zh.m4
 m4/codeset.m4
 
 Depends-on:
+setlocale
 
 configure.ac:
 gt_LOCALE_ZH_CN