add `auto` keyword, parse `auto trait`, lower to HIR

Adds an `IsAuto` field to `ItemTrait` which flags if the trait was
declared as an `auto trait`.

Auto traits cannot have generics nor super traits.

1 files changed, 6 insertions, 5 deletions

diff --git a/src/libsyntax_pos/symbol.rs b/src/libsyntax_pos/symbol.rs
index 872fc031cfb..26e6f27e20f 100644
--- a/src/libsyntax_pos/symbol.rs
+++ b/src/libsyntax_pos/symbol.rs
@@ -309,11 +309,12 @@ declare_keywords! {
     (54, Yield,          "yield")
 
     // Weak keywords, have special meaning only in specific contexts.
-    (55, Catch,          "catch")
-    (56, Default,        "default")
-    (57, Dyn,            "dyn")
-    (58, StaticLifetime, "'static")
-    (59, Union,          "union")
+    (55, Auto,           "auto")
+    (56, Catch,          "catch")
+    (57, Default,        "default")
+    (58, Dyn,            "dyn")
+    (59, StaticLifetime, "'static")
+    (60, Union,          "union")
 }
 
 // If an interner exists in TLS, return it. Otherwise, prepare a fresh one.