add rustc-dep-of-std feature

Author: newpavlov

Cargo.toml

@@ -12,6 +12,13 @@ readme = "README.md"
 documentation = "https://docs.rs/wasi"
 
 [dependencies]
+# When built as part of libstd
+compiler_builtins = { version = "0.1", optional = true }
+core = { version = "1.0", optional = true, package = "rustc-std-workspace-core" }
+
+[features]
+# Unstable feature to support being a libstd dependency
+rustc-dep-of-std = ["compiler_builtins", "core"]
 
 [badges]
 maintenance = { status = "experimental" }