Emerge Yul recompiler (#1)

Provide a modified (and incomplete) version of ZKSync zksolc that can compile the most basic contracts

crates/solidity/src/project/contract/metadata.rs

@@ -0,0 +1,45 @@
+//!
+//! The Solidity contract metadata.
+//!
+
+use serde::Serialize;
+
+///
+/// The Solidity contract metadata.
+///
+/// Is used to append the metadata hash to the contract bytecode.
+///
+#[derive(Debug, Serialize)]
+pub struct Metadata {
+    /// The `solc` metadata.
+    pub solc_metadata: serde_json::Value,
+    /// The `solc` version.
+    pub solc_version: semver::Version,
+    /// The zkVM `solc` edition.
+    pub solc_zkvm_edition: Option<semver::Version>,
+    /// The EraVM compiler version.
+    pub zk_version: semver::Version,
+    /// The EraVM compiler optimizer settings.
+    pub optimizer_settings: era_compiler_llvm_context::OptimizerSettings,
+}
+
+impl Metadata {
+    ///
+    /// A shortcut constructor.
+    ///
+    pub fn new(
+        solc_metadata: serde_json::Value,
+        solc_version: semver::Version,
+        solc_zkvm_edition: Option<semver::Version>,
+        zk_version: semver::Version,
+        optimizer_settings: era_compiler_llvm_context::OptimizerSettings,
+    ) -> Self {
+        Self {
+            solc_metadata,
+            solc_version,
+            solc_zkvm_edition,
+            zk_version,
+            optimizer_settings,
+        }
+    }
+}