and make 5c, 8c use them.
centralizes reachability analysis
and switch generation.
now 8c doesn't have spurious warnings
in pkg/runtime.
R=ken
OCL=31266
CL=31266
these guys really really want long to be 32-bits,
so ,s/long/int32/ (and then manual fixup).
still passes all tests.
(i started out looking for just those longs that
needed to be int32 instead, and it was just too hard
to track them down one by one.)
the longs were rare enough that i don't think
it will cause integration problems.
R=ken
OCL=13787
CL=13789
