[cogl] Non-fast-forward update to branch cogl.windows.fixes

[Chun-wei Fan <fanchunwei src gnome org>]

The branch 'cogl.windows.fixes' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  bbc97b4... cogl/cogl-debug.h: Export and properly use extern variables

Commits added to the branch:

  f51c248... cogl/cogl-debug.h: Export and properly use _cogl_debug_inst