Upcoming changes

[Raymond Toy]

Just wanted to make a note that for the next snapshot a basic cross-compile
is needed.  For x86, the cross-compile fixes a bug in
tracing/debug:arg for sse2 builds.  Any floating-point values were
basically random.

In addition, two new slots are being added to fd-streams.  The two new
slots are not yet used but will be used to control how errors are
handled in stream I/O.  This also uses a cross-compile.  When the
cross-compile complains about incompatible structures, just select the
CLOBBER-IT restart each time cmucl complains.

Ray