Initial public commit of regalloc2.

fuzz/fuzz_targets/ion.rs

@@ -0,0 +1,11 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+
+use regalloc2::fuzzing::func::Func;
+
+fuzz_target!(|func: Func| {
+    let _ = env_logger::try_init();
+    log::debug!("func:\n{:?}", func);
+    let env = regalloc2::fuzzing::func::machine_env();
+    let _out = regalloc2::ion::run(&func, &env).expect("regalloc did not succeed");
+});