sparc: use correct printf format spec for int32_t

This avoids strangely large positive numbers instead of negative offsets
on x86_64 hosts.
be: use designated initializer for regs, regclasses, reg_reqs
bearch: cleanup, improve struct packing
amd64: Floating point register permutation
Only compute global entity usage if alias analysis is enabled.

The global analysis has quadratic worst-case complexity in the number of
graphs.  At least if alias analysis is disabled anyway, this can be
avoided.
bepeephole: check assigned entities in be_can_move_down()

This fixes a subtle bug where the delay slot filler would move a
spill/reload across a MemPerm although they both share a spillslot.