CWARNFALGS.$file centrally so we don't have to have it in all the
places. Remove a few warning flags that are no longer needed.
Also, always use -Wno-unknown-pragma to (hopefully temporarily) work
around #pragma ident in debug.h in the opensolaris code. Remove some
stale warning suppression that's no longer necessary.
with clang:
sys/dev/ce/tau32-ddk.c:1228:37: warning: implicit truncation from 'int' to bitfield changes value from 65532 to 8188 [-Wconstant-conversion]
Since this file is obfuscated C, we can never determine (in a sane way,
at least :) if this points to a real problem or not. The driver has
been in the tree for more than five years, so it most likely isn't.
MFC after: 1 week