fix(rustup): nightly rust moved Registry into rustc_plugin

serde_codegen/src/lib.rs

@@ -14,7 +14,7 @@ extern crate syntex_syntax as syntax;
 extern crate syntax;
 
 #[cfg(not(feature = "with-syntex"))]
-extern crate rustc;
+extern crate rustc_plugin;
 
 #[cfg(feature = "with-syntex")]
 include!(concat!(env!("OUT_DIR"), "/lib.rs"));
@@ -60,7 +60,7 @@ pub fn register(reg: &mut syntex::Registry) {
 }
 
 #[cfg(not(feature = "with-syntex"))]
-pub fn register(reg: &mut rustc::plugin::Registry) {
+pub fn register(reg: &mut rustc_plugin::Registry) {
     reg.register_syntax_extension(
         syntax::parse::token::intern("derive_Serialize"),
         syntax::ext::base::MultiDecorator(