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/lock.rs

@@ -0,0 +1,37 @@
+//! The revive LLVM builder lock file.
+
+use anyhow::Context;
+use std::fs::File;
+use std::io::Read;
+use std::path::PathBuf;
+
+use serde::Deserialize;
+use serde::Serialize;
+
+/// The default lock file location.
+pub const LLVM_LOCK_DEFAULT_PATH: &str = "LLVM.lock";
+
+/// The lock file data.
+///
+/// This file describes the exact reference of the LLVM framework.
+#[derive(Debug, Deserialize, Serialize)]
+pub struct Lock {
+    /// The LLVM repository URL.
+    pub url: String,
+    /// The LLVM repository branch.
+    pub branch: String,
+    /// The LLVM repository commit reference.
+    pub r#ref: Option<String>,
+}
+
+impl TryFrom<&PathBuf> for Lock {
+    type Error = anyhow::Error;
+
+    fn try_from(path: &PathBuf) -> Result<Self, Self::Error> {
+        let mut config_str = String::new();
+        let mut config_file =
+            File::open(path).with_context(|| format!("Error opening {:?} file", path))?;
+        config_file.read_to_string(&mut config_str)?;
+        Ok(toml::from_str(&config_str)?)
+    }
+}