Work around wrong vsscanf() declaration under HP-UX.

Under this system vsscanf() is declared as taking a non-const char* as first
argument which prevented our code using it from compiling. Wrap it in
wxCRT_VsscanfA() adding the necessary const_cast<> to fix this.

Closes #15638.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75340 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/wxcrtvararg.h

@@ -238,7 +238,17 @@
 #define wxCRT_ScanfA     scanf
 #define wxCRT_SscanfA    sscanf
 #define wxCRT_FscanfA    fscanf
-#define wxCRT_VsscanfA   vsscanf
+
+/* vsscanf() may have a wrong declaration with non-const first parameter, fix
+ * this by wrapping it if necessary. */
+#if defined __cplusplus && defined HAVE_BROKEN_VSSCANF_DECL
+    inline int wxCRT_VsscanfA(const char *str, const char *format, va_list ap)
+    {
+        return vsscanf(const_cast<char *>(str), format, ap);
+    }
+#else
+    #define wxCRT_VsscanfA   vsscanf
+#endif
 
 #if defined(wxNEED_WPRINTF)
     int wxCRT_ScanfW(const wchar_t *format, ...);