1.45_08: Replace each %hash with foreach keys (#307)

In B::C, Bytecode and CC.
The big issues were only hash traversal (B::HV::hwalk) in Bytecode
and B::walksymtable in B::C
CC: keep each %$declare
each-hash: skip new B::C::walksymtable also
de-randomize all foreach keys to sort

we better have predictable and comparable hash key ordering (syms, packages, ...)