implement floats by running the ops on the host architecture

optimize all ZST allocations into one single allocation

things priroda needs to be public or changed

use the item path printer that prints user friendly textual paths

don't execute the first statement of a constant/static/promoted right away

This might create confusion, because attempting to execute a statement can cause
arbitrary stackframes to be added for the constants/statics/promoteds required by that
statement. Before this commit, the first statement of the last added stackframe was
executed immediately. Thus there was no way to inspect the state before that first
statement.

Use target byte order instead of host byteorder

use ty::layout::Size and ty::layout::TargetDataLayout

implement char handling

cleanup overflow binop code