EarlyFunctionAnalysis now can be invoked to schedule a full
ABI analysis over the collected functions via `--detect-abi`
option, or it can limit itself to simply recover the CFG and
serialize it onto the LLVM IR via `--collect-cfg` option.
The control-flow graph and all its hierarchy components
have been moved from `model` to `efa`. The CFG is now
serialized onto the LLVM IR module as a metadata.
The results of the model are loaded into the EarlyFunctionAnalysis
cache, and only those functions which are not in the model have
an EarlyFunctionAnalysis scheduled. The model is updated appropriately.
The collection of the function entry-points has now been separated
from EarlyFunctionAnalysis into two distinct passes: the first one,
which collects functions which are in call-sites of a direct call,
and the second one which collects code pointers in `.rodata` (e.g.,
function pointers, vtables; jump-tables are possibly skipped).