alnyan/yggdrasil: build as std dependency

Cargo.toml

@@ -15,6 +15,8 @@ exclude = ["/ci/", "/.github/workflows/"]
 [features]
 default = []
 
+checked = []
+
 # This tells the compiler to assume that a Nightly toolchain is being used and
 # that it should activate any useful Nightly things accordingly.
 unstable = []
@@ -23,12 +25,18 @@ unstable = []
 # musl libc.
 musl-reference-tests = ['rand']
 
+rustc-dep-of-std = ["core", "compiler_builtins/rustc-dep-of-std"]
+
 [workspace]
 members = [
   "crates/compiler-builtins-smoke-test",
   "crates/libm-bench",
 ]
 
+[dependencies]
+core = { version = "1.0.0", optional = true, package = "rustc-std-workspace-core" }
+compiler_builtins = { version = "0.1", optional = true }
+
 [dev-dependencies]
 no-panic = "0.1.8"
 

build.rs

@@ -6,6 +6,9 @@ fn main() {
     #[cfg(feature = "musl-reference-tests")]
     musl_reference_tests::generate();
 
+    println!("cargo:rustc-check-cfg=cfg(assert_no_panic)");
+    println!("cargo:rustc-check-cfg=cfg(rustfmt)");
+
     if !cfg!(feature = "checked") {
         let lvl = env::var("OPT_LEVEL").unwrap();
         if lvl != "0" {