Relative addreses (wrt EIP/RIP) are now available as effective addresses.
Control flow graphs.

The module `QQLeLe.CFG` implements mutable control flow graphs via a
monad transformer `CFGT`. Any representation of basic blocks may be
used, as long as it's an instance of `BBlock`. The predecessor and
successor relations are automatically maintained.
CFG traversal and some random fixes.
Attributes for basic blocks.
SSA representation for basic blocks.

Instead of having phi instructions, each basic block has a list of
input variables whose values are passed at jump site. The obvious
advantage is that basic blocks do not have to be modified when new
predecessors are added.