Bit 12 of render->aux1 is GL_CCW/GL_CW. For GL_CCW (default of glFrontFace) we have
to set that bit active.

This is not what the blob does and what the original reverse engineering documentation
says. The blob sets this value inverted and does some bogus negation of the fragment
shaders gl_FrontFacing variable instead.

Anyway, doing it this way does not cause regressions but fixes
dEQP-GLES2.functional.shaders.builtin_variable.frontfacing and 4 piglit tests.

Signed-off-by: Andreas Baierl <ichgeh@imkreisrum.de>