Build support for no llvm

src/bootstrap/native.rs

@@ -56,6 +56,12 @@ impl Step for Llvm {
     fn run(self, builder: &Builder) {
         let build = builder.build;
         let target = self.target;
+
+        // If we're not compiling for LLVM bail out here.
+        if !build.config.llvm_enabled {
+            return;
+        }
+
         // If we're using a custom LLVM bail out here, but we can only use a
         // custom LLVM for the build triple.
         if let Some(config) = build.config.target_config.get(&target) {