This commit drops libptc in favor of its new form libtcg.
It brings several improvements, among which:
* The QEMU version we work on has been upgraded.
* CPUStateAccessAnalysis has been reimplemented in a way that makes it
easier to debug and solves some limitations (e.g., tracking leaking
pointers).
* Identification of pieces of the CPU state that are read by each helper
and fixing access to the CPU state is now performed at build-time.
* We no longer mmap the code we need to translate, dropping all the
issues related to code that needed to be mapped where something is
already present.
* We now have two distinct flavors of helper modules: the full one and
the "slim" one. The latter contains the definition only of functions
we intend to inline. It is used in most of the pipeline, a good thing
since we spend less time optimizing code we don't really care about.
The full module is only used on the re-compilation branch of the
pipeline.
* We no longer split the `cpu_loop` function.
* We change MetaAddress to rely on architectures from `model::` as
opposed to the LLVM ones.
* We no longer attach debug info to LLVM IR containing the original
assembly.
* We now verify that the lifted code only contains code we expect.
Previously revng pipe did not correctly propagate targets from input
containers into output containers based on the pipe contract. This
happened to work for pipes acting on LLVM containers where the same
container is used for input and output, but failed for the Clift backend
pipe, where an MLIR container is used for input and a string map
container is used for output.
Drop using the `revng-` prefix from all executables under
`libexec/revng/`. Now any executable found under there that is
executable and without extension will be considered a `revng`
subcommand, following the usual command-line rules.
Lauri Vasama