* modules/wctrans: New file.
* lib/wctype.in.h (wctrans): New declaration.
* lib/wctrans.c: New file.
* lib/wctrans-impl.h: New file.
* m4/wctrans.m4: New file.
* m4/wctype_h.m4 (gl_WCTYPE_H): Test whether wctrans is declared.
(gl_WCTYPE_H_DEFAULTS): Initialize GNULIB_WCTRANS.
* modules/wctype-h (Makefile.am): Substitute GNULIB_WCTRANS.
* tests/test-wctype-h-c++.cc: Test the declaration of wctrans.
* doc/posix-functions/wctrans.texi: Mention the new module.