LLVM 9 drops the `TerminatorInst` class. This commit replaces it with
`Instruction` where possible and asserts
`Instruction::isTerminator()`. It also switches from
`TerminatorInst::successors` to `successors(TerminatorInst *)`.
This commit enlarges the set of external function calls we
detect. Basically, instead of assuming that the instruction jumping to
the external function is the call, we now also consider instructions in
previous basic blocks, as long as there's only one possible path
backward.
This commit does the following:
* It drops `revamb-dump` and transforms all the passes it featured in
passes that can be used directly from `opt`.
* It rename `revamb` to `revng-lift`.
* It introduces a script called `revng` which acts as a driver for the
whole rev.ng project. It replaces `translate`, `revcc`,
`csv-to-ld-options` and `revamb-dump`, since it offers an `opt`
subcommand which allows to easily invoke all the analysis passes.
* It makes the project a CMake package that can be easily used
externally.
* It allows to easily create libraries of analysis to use through
`revng-opt`.
Alessandro Di Federico