crt: wctype: add support for "blank" character class

Add support for "blank" character class to provide C99 conforming implementaion
of `wctype` function for all CRTs up to msvcr110.dll; msvcr120.dll and UCRT
provide C99 conforming `wctype` function.

Signed-off-by: Kirill Makurin <maiddaisuki@outlook.com>
Signed-off-by: LIU Hao <lh_mouse@126.com>

mingw-w64-crt/misc/wctype.c

diff --git a/mingw-w64-crt/misc/wctype.c b/mingw-w64-crt/misc/wctype.c
index 1b3a3f8..f7ad8ed 100644
--- a/mingw-w64-crt/misc/wctype.c
+++ b/mingw-w64-crt/misc/wctype.c
@@ -21,6 +21,7 @@
 
   iswctype(wc, wctype("alnum")) == iswalnum(wc)
   iswctype(wc, wctype("alpha")) == iswalpha(wc)
+  iswctype(wc, wctype("blank")) == iswblank(wc)
   iswctype(wc, wctype("cntrl")) == iswcntrl(wc)
   iswctype(wc, wctype("digit")) == iswdigit(wc)
   iswctype(wc, wctype("graph")) == iswgraph(wc)
@@ -44,6 +45,7 @@
 } cmap[] = {
   {"alnum",  _ALPHA|_DIGIT},
   {"alpha",  _ALPHA},
+  {"blank",  _BLANK},
   {"cntrl",  _CONTROL},
   {"digit",  _DIGIT},
   {"graph",  _ALPHA|_DIGIT|_PUNCT},