include widec.h if it's available, it contains declarations of [f]putws() under Solaris

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@43227 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

configure.in

@@ -4530,7 +4530,21 @@ if test "$wxUSE_UNICODE" = yes; then
         fi
     fi
 
-    WX_CHECK_FUNCS(wputc wputchar putws fputws wprintf vswprintf)
+    dnl also look if we have wide char IO functions, notice that [f]putws are
+    dnl declared in special widec.h under Solaris
+    wchar_headers="#include <stdio.h>
+#include <wchar.h>"
+    case "${host}" in
+        *-*-solaris2* )
+            AC_CHECK_HEADERS(widec.h)
+            if test "$ac_cv_header_widec_h" = "yes"; then
+                wchar_headers="$wchar_headers
+#include <widec.h>"
+            fi
+    esac
+
+    WX_CHECK_FUNCS(wputc wputchar putws fputws wprintf vswprintf,,,
+                   [$wchar_headers])
 
     dnl MinGW has a vswprintf with a different prototype, and
     dnl a _vsnwprintf with the correct prototype, but AC_CHECK_FUNCS