Bit 12 of render->aux1 is GL_CCW/GL_CW. For GL_CCW (default of glFrontFace) we have
to set that bit active. Until now, this bit was always set and all ohter tests passed,
so we can conclude, that 0x1000 is the default value (GL_CCW) anyway.

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.
The blob fails with dEQP-GLES2.funtional.shaders.builtin_variable.frontfacing btw.

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>