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/stdlib/Cargo.toml

@@ -8,3 +8,6 @@ description = "revive compiler stdlib components"
 
 [dependencies]
 inkwell = { workspace = true, features = ["target-riscv", "no-libffi-linking", "llvm18-0"] }
+
+[build-dependencies]
+revive-build-utils = { workspace = true }

crates/stdlib/build.rs

@@ -1,18 +1,23 @@
 use std::{env, fs, path::Path, process::Command};
 
 fn main() {
+    println!(
+        "cargo:rerun-if-env-changed={}",
+        revive_build_utils::REVIVE_LLVM_HOST_PREFIX
+    );
+
     let lib = "stdlib.bc";
     let out_dir = env::var_os("OUT_DIR").expect("env should have $OUT_DIR");
     let bitcode_path = Path::new(&out_dir).join(lib);
-
-    let output = Command::new("llvm-as")
+    let llvm_as = revive_build_utils::llvm_host_tool("llvm-as");
+    let output = Command::new(llvm_as)
         .args([
             "-o",
             bitcode_path.to_str().expect("$OUT_DIR should be UTF-8"),
             "stdlib.ll",
         ])
         .output()
-        .expect("should be able to invoke llvm-as");
+        .unwrap_or_else(|error| panic!("failed to execute llvm-as: {}", error));
 
     assert!(
         output.status.success(),