Add ptr_to_compat() - needed by the new robust futex code.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>