Only add rustc_randomized_layouts if the crate has it

Author: GuillaumeGomez

src/bootstrap/src/lib.rs

@@ -683,7 +683,7 @@ impl Build {
             features.push("llvm");
         }
         // keep in sync with `bootstrap/compile.rs:rustc_cargo_env`
-        if self.config.rust_randomize_layout {
+        if self.config.rust_randomize_layout && check("rustc_randomized_layouts") {
             features.push("rustc_randomized_layouts");
         }