auto merge of #13184 : alexcrichton/rust/priv-fields, r=brson

This is an implementation of a portion of [RFC #4](https://github.com/rust-lang/rfcs/blob/master/active/0004-private-fields.md). This PR makes named struct fields private by default (as opposed to inherited by default).

The only real meaty change is the first commit to `rustc`, all other commits are just fallout of that change.

Summary of changes made:

* Named fields are private by default *everywhere*
* The `priv` keyword is now default-deny on named fields (done in a "lint" pass in privacy)

Changes yet to be done (before the RFC is closed)

* Change tuple structs to have private fields by default
* Remove `priv` enum variants
* Make `priv` a reserved keyword

1 files changed, 4 insertions, 4 deletions

diff --git a/src/doc/tutorial.md b/src/doc/tutorial.md
index e15145e5f1d..3423a5e090e 100644
--- a/src/doc/tutorial.md
+++ b/src/doc/tutorial.md
@@ -2657,8 +2657,8 @@ Rust doesn't support encapsulation: both struct fields and methods can
 be private. But this encapsulation is at the module level, not the
 struct level.
 
-For convenience, fields are _public_ by default, and can be made _private_ with
-the `priv` keyword:
+Fields are _private_ by default, and can be made _public_ with
+the `pub` keyword:
 
 ~~~
 mod farm {
@@ -2667,8 +2667,8 @@ mod farm {
 # impl Human { pub fn rest(&self) { } }
 # pub fn make_me_a_farm() -> Farm { Farm { chickens: ~[], farmer: Human(0) } }
     pub struct Farm {
-        priv chickens: ~[Chicken],
-        farmer: Human
+        chickens: ~[Chicken],
+        pub farmer: Human
     }
 
     impl Farm {