Emerge Yul recompiler (#1)

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

crates/llvm-context/src/target_machine/target.rs

@@ -0,0 +1,66 @@
+//!
+//! The LLVM target.
+//!
+
+use std::str::FromStr;
+
+///
+/// The LLVM target.
+///
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Target {
+    /// The EraVM target.
+    PVM,
+}
+
+impl Target {
+    ///
+    /// Returns the target name.
+    ///
+    pub fn name(&self) -> &str {
+        match self {
+            Self::PVM => "riscv32",
+        }
+    }
+
+    ///
+    /// Returns the target triple.
+    ///
+    pub fn triple(&self) -> &str {
+        match self {
+            Self::PVM => "riscv32-unknown-unknown-elf",
+        }
+    }
+
+    ///
+    /// Returns the target production name.
+    ///
+    pub fn production_name(&self) -> &str {
+        match self {
+            Self::PVM => "PVM",
+        }
+    }
+}
+
+impl FromStr for Target {
+    type Err = anyhow::Error;
+
+    fn from_str(string: &str) -> Result<Self, Self::Err> {
+        match string {
+            "riscv32" => Ok(Self::PVM),
+            _ => Err(anyhow::anyhow!(
+                "Unknown target `{}`. Supported targets: {:?}",
+                string,
+                Self::PVM
+            )),
+        }
+    }
+}
+
+impl std::fmt::Display for Target {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Target::PVM => write!(f, "riscv32"),
+        }
+    }
+}