mesa: change GL_ALL_ATTRIB_BITS to 0xFFFFFFFF

mesa: change GL_ALL_ATTRIB_BITS to 0xFFFFFFFF

This has been wrong for many years.  It was originally 0x000FFFFF and long
ago there was discussion about whether GL_ALL_ATTRIB_BITS should include
the then-new GL_MULTISAMPLE_BIT bit.  Eventually the ARB decided that
glPushAttrib(GL_ALL_ATTRIB_BITS) should save all current and future
attribute groups (hence ~0).  Unfortunately, Mesa's gl.h was never updated.

This was just recently spotted by Eric Anholt and reported as a bug to the
ARB.  Ian, Jon Leech and I discussed it at the ARB meeting and decided to
change Mesa's value to reflect the ARB's decision.

Acked-by: Eric Anholt <eric@anholt.net>