message: Set language tag on win32 text controls
  Set language on translation text controls so that the information is
  present for a11y tools, possibly spellcheckers etc.
  Notice that this does _not_ cause Windows builtin spellchecker to
  recognize the language of the text on Windows 10.
diff: @@ -604,6 +604,15 @@ void AnyTranslatableTextCtrl::SetLanguage(const Language& lang)
  ::SendMessage((HWND)GetHWND(), EM_SETEDITSTYLE, lang.IsRTL() ? SES_BIDI : 0, SES_BIDI);
  + CHARFORMAT2 cf;
  + ::ZeroMemory(&cf, sizeof(cf));
  + cf.cbSize = sizeof(cf);
  + cf.dwMask = CFM_LCID;
  + cf.lcid = LocaleNameToLCID(str::to_wstring(m_language.LanguageTag()).c_str(), 0);
  + if (cf.lcid == 0)
  + cf.lcid = LOCALE_USER_DEFAULT;
  + ::SendMessage((HWND)GetHWND(), EM_SETCHARFORMAT, SCF_ALL, (LPARAM)&cf);
  +
  UpdateRTLStyle();
  #endif
  }
  