resolc crate (#328)

- Factor the YUL crate out of `revive-solidity`.
- `revive-solidity` is in reality not a Solidity implementation but the
revive solidity compiler driver (`resolc`). By renaming we not only get
this straight but also a binary with the same name as the crate which
should be less confusing.

---------

Signed-off-by: Cyrill Leutwiler <bigcyrill@hotmail.com>

crates/resolc/src/solc/mod.rs

@@ -0,0 +1,50 @@
+//! The Solidity compiler.
+
+#[cfg(not(target_os = "emscripten"))]
+pub mod solc_compiler;
+#[cfg(target_os = "emscripten")]
+pub mod soljson_compiler;
+pub mod version;
+
+use std::path::Path;
+use std::path::PathBuf;
+
+use revive_solc_json_interface::combined_json::CombinedJson;
+use revive_solc_json_interface::SolcStandardJsonInput;
+use revive_solc_json_interface::SolcStandardJsonOutput;
+
+use self::version::Version;
+
+/// The first version of `solc` with the support of standard JSON interface.
+pub const FIRST_SUPPORTED_VERSION: semver::Version = semver::Version::new(0, 8, 0);
+
+/// The last supported version of `solc`.
+pub const LAST_SUPPORTED_VERSION: semver::Version = semver::Version::new(0, 8, 30);
+
+/// `--include-path` was introduced in solc `0.8.8` <https://github.com/ethereum/solidity/releases/tag/v0.8.8>
+pub const FIRST_INCLUDE_PATH_VERSION: semver::Version = semver::Version::new(0, 8, 8);
+
+/// The Solidity compiler.
+pub trait Compiler {
+    /// Compiles the Solidity `--standard-json` input into Yul IR.
+    fn standard_json(
+        &mut self,
+        input: SolcStandardJsonInput,
+        base_path: Option<String>,
+        include_paths: Vec<String>,
+        allow_paths: Option<String>,
+    ) -> anyhow::Result<SolcStandardJsonOutput>;
+
+    /// The `solc --combined-json abi,hashes...` mirror.
+    fn combined_json(
+        &self,
+        paths: &[PathBuf],
+        combined_json_argument: &str,
+    ) -> anyhow::Result<CombinedJson>;
+
+    /// The `solc` Yul validator.
+    fn validate_yul(&self, path: &Path) -> anyhow::Result<()>;
+
+    /// The `solc --version` mini-parser.
+    fn version(&mut self) -> anyhow::Result<Version>;
+}