revive llvm builder utility (#154)

Pre-eliminary support for LLVM releases and resolc binary releases by streamlining the build process for all supported hosts platforms.

- Introduce the revive-llvm-builder crate with the revive-llvm builder utilty.
- Do not rely on the LLVM dependency in $PATH to decouple the system LLVM installation from the LLVM host dependency.
- Fix the emscripten build by decoupling the host and native LLVM dependencies. Thus allowing a single LLVM emscripten release that can be used on any host platform.
- An example Dockerfile building an alpine container with a fully statically linked resolc ELF binary.
- Remove the Debian builder utilities and workflow.

crates/llvm-builder/src/target_env.rs

@@ -0,0 +1,36 @@
+//! The target environments to build LLVM.
+
+/// The list of target environments used as constants.
+#[derive(Default, Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum TargetEnv {
+    /// The GNU target environment.
+    #[default]
+    GNU,
+    /// The MUSL target environment.
+    MUSL,
+    /// The wasm32 Emscripten environment.
+    Emscripten,
+}
+
+impl std::str::FromStr for TargetEnv {
+    type Err = String;
+
+    fn from_str(value: &str) -> Result<Self, Self::Err> {
+        match value {
+            "gnu" => Ok(Self::GNU),
+            "musl" => Ok(Self::MUSL),
+            "emscripten" => Ok(Self::Emscripten),
+            value => Err(format!("Unsupported target environment: `{}`", value)),
+        }
+    }
+}
+
+impl std::fmt::Display for TargetEnv {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::GNU => write!(f, "gnu"),
+            Self::MUSL => write!(f, "musl"),
+            Self::Emscripten => write!(f, "emscripten"),
+        }
+    }
+}