identifies current thread.
- Make X11DRV_GetKeyboardLayoutList follow the same rule as
  X11DRV_GetKeyboardLayout and X11DRV_GetKeyboardLayoutName for CJK
  locales.
- There is no need to have 0xe001 in the high word of Japanese
  keyboard layouts lcids in main_key_tab, the above APIs take care of
  it.
- High word of a returned keyboard layout duplicates low word for non
  CJK locales under Windows.