Allow to use clang++ with CUDA compiler.

CUDA compiler supports clang++, but it wasn't possible to use it with
cc-rs, because --target option was passed to nvcc instead of clang.

src/lib.rs

@@ -1690,7 +1690,7 @@ impl Build {
                             cmd.args.push("--target=aarch64-unknown-windows-gnu".into())
                         }
                     } else {
-                        cmd.args.push(format!("--target={}", target).into());
+                        cmd.push_cc_arg(format!("--target={}", target).into());
                     }
                 }
             }