When using gcc 3.3.3 on alpha, the current BK head doesn't compile.

- there's an external declaration for abs() in the same scope as a macro
  definition in arch/alpha/time.c

- The compiler is picky about `const' declarations, which breaks on
  bitops.h.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>