Log Message:
Update to 2.3.8:

Adam Jackson (2):
      Use own thunk function instead of vgaHW*Weak
      dri: Stop (uselessly) initializing the ValidateTree hooks

Jeremy White (1):
      Include xf86Modes.h to use functions from hw/xfree86/modes/xf86Modes.c.

Julien Cristau (2):
      Fix compiler warnings with recent X servers
      Bump to 2.3.8