[analysis][NFC] Create a TransferFunction concept (#6033)

Factor the static assertions for transfer functions out into a new
transfer-function.h header. The concept requires the `getDependents` method to
return an input range of basic blocks, and to satisfy that requirement, fix up
_indirect_ptr_iterator in cfg-impl.h so that it is a proper iterator. Remove
part of the lattice fuzzer that was using a placeholder transfer function in a
way that does not satisfy the new type constraints; most of that code will be
overhauled in the future anyway.

0 files changed, 0 insertions, 0 deletions