only run --all-targets in stage0

Author: jo3bingham

src/bootstrap/check.rs

@@ -140,7 +140,10 @@ impl Step for Std {
             cargo_subcommand(builder.kind),
         );
 
-        cargo.arg("--all-targets");
+        if compiler.stage == 0 {
+            cargo.arg("--all-targets");
+        }
+
         std_cargo(builder, target, compiler.stage, &mut cargo);
 
         // Explicitly pass -p for all dependencies krates -- this will force cargo