[XFS] Keep stack usage down for 4k stacks by using noinline.

gcc-4.1 and more recent aggressively inline static functions which
increases XFS stack usage by ~15% in critical paths. Prevent this from
occurring by adding noinline to the STATIC definition.

Also uninline some functions that are too large to be inlined and were
causing problems with CONFIG_FORCED_INLINING=y.

Finally, clean up all the different users of inline, __inline and
__inline__ and put them under one STATIC_INLINE macro. For debug kernels
the STATIC_INLINE macro uninlines those functions.

SGI-PV: 957159
SGI-Modid: xfs-linux-melb:xfs-kern:27585a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: David Chatterton <chatz@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>