Auto merge of #28535 - petrochenkov:name, r=nrc

Part of https://github.com/rust-lang/rust/issues/6993

This patch replaces `Ident`s with `Name`s in data structures of HIR and updates the dependent crates to compile and pass `make check`.
Some HIR structures still use `Ident`s, namely `PathSegment`, `PatIdent`, `ExprWhile`, `ExprLoop`, `ExprBreak` and `ExprAgain`,  they need them for resolve (but `PathSegment` is special, see https://github.com/rust-lang/rust/issues/6993#issuecomment-141256292).

r? @nrc 

1 files changed, 13 insertions, 2 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 5b04fc0e697..62eb6022d0c 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -151,8 +151,7 @@ pub const ILLEGAL_CTXT : SyntaxContext = 1;
 
 /// A name is a part of an identifier, representing a string or gensym. It's
 /// the result of interning.
-#[derive(Eq, Ord, PartialEq, PartialOrd, Hash,
-           RustcEncodable, RustcDecodable, Clone, Copy)]
+#[derive(Eq, Ord, PartialEq, PartialOrd, Hash, Clone, Copy)]
 pub struct Name(pub u32);
 
 impl<T: AsRef<str>> PartialEq<T> for Name {
@@ -179,6 +178,18 @@ impl Name {
 /// A mark represents a unique id associated with a macro expansion
 pub type Mrk = u32;
 
+impl Encodable for Name {
+    fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
+        s.emit_str(&self.as_str())
+    }
+}
+
+impl Decodable for Name {
+    fn decode<D: Decoder>(d: &mut D) -> Result<Name, D::Error> {
+        Ok(token::intern(&try!(d.read_str())[..]))
+    }
+}
+
 impl Encodable for Ident {
     fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
         s.emit_str(&self.name.as_str())