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/tests/common.rs

@@ -0,0 +1,36 @@
+use assert_fs::fixture::FileWriteStr;
+
+pub const REVIVE_LLVM: &str = "revive-llvm";
+pub const REVIVE_LLVM_REPO_URL: &str = "https://github.com/llvm/llvm-project";
+pub const REVIVE_LLVM_REPO_TEST_BRANCH: &str = "release/18.x";
+
+pub struct TestDir {
+    _lockfile: assert_fs::NamedTempFile,
+    path: std::path::PathBuf,
+}
+
+/// Creates a temporary lock file for testing.
+impl TestDir {
+    pub fn with_lockfile(reference: Option<String>) -> anyhow::Result<Self> {
+        let file =
+            assert_fs::NamedTempFile::new(revive_llvm_builder::lock::LLVM_LOCK_DEFAULT_PATH)?;
+        let lock = revive_llvm_builder::Lock {
+            url: REVIVE_LLVM_REPO_URL.to_string(),
+            branch: REVIVE_LLVM_REPO_TEST_BRANCH.to_string(),
+            r#ref: reference,
+        };
+        file.write_str(toml::to_string(&lock)?.as_str())?;
+
+        Ok(Self {
+            path: file
+                .parent()
+                .expect("lockfile parent dir always exists")
+                .into(),
+            _lockfile: file,
+        })
+    }
+
+    pub fn path(&self) -> &std::path::Path {
+        &self.path
+    }
+}