Fix one error and compiler warnings with Cuda & clang-3.6

Fix one error and compiler warnings with Cuda & clang-3.6

Clang-3.6 on OS X can now be used by nvcc. clang found one
error related to || being used instead of | to set flag bits,
and a handful of warnings variables in headers not being used.
The latter is caused by declaring constants in headers, and
making then static to avoid clashing symbols. However, this emits
them in every single compile unit that includes the header. Fixed
by either moving names to a cpp file, or changing to defines.

Change-Id: Ib4d59c40aa8caffc667cc202a3efe45891b2abe3