Update syn to 0.12 and quote to 0.4

Author: Eijebong

html5ever/Cargo.toml

@@ -41,5 +41,6 @@ rustc-test = "0.2"
 typed-arena = "1.3.0"
 
 [build-dependencies]
-quote = "0.3.3"
-syn = { version = "0.11", features = ["full", "visit"] }
+quote = "0.4"
+syn = { version = "0.12", features = ["extra-traits", "full", "fold"] }
+proc-macro2 = "0.2"

html5ever/build.rs

@@ -8,7 +8,8 @@
 // except according to those terms.
 
 #[macro_use] extern crate quote;
-extern crate syn;
+#[macro_use] extern crate syn;
+extern crate proc_macro2;
 
 use std::env;
 use std::path::Path;
@@ -20,7 +21,7 @@ fn main() {
     let manifest_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
 
     let rules_rs = Path::new(&manifest_dir).join("src/tree_builder/rules.rs");
-    match_token::expand_match_tokens(
+    match_token::expand(
         &rules_rs,
         &Path::new(&env::var("OUT_DIR").unwrap()).join("rules.rs"));