Integrate Lightbeam (#51)

* Integrate lightbeam

wasmtime-jit/Cargo.toml

@@ -30,6 +30,7 @@ wasmparser = "0.29.2"
 default = ["std"]
 std = ["cranelift-codegen/std", "cranelift-wasm/std"]
 core = ["hashbrown/nightly", "cranelift-codegen/core", "cranelift-wasm/core", "wasmtime-environ/core"]
+lightbeam = ["wasmtime-environ/lightbeam"]
 
 [badges]
 maintenance = { status = "experimental" }