Fix broken Markdown and bad links in the error index

This makes sure RFC links point to the RFC text not the pull request.

src/librustc/diagnostics.rs

@@ -1336,7 +1336,7 @@ trait SecondTrait : FirstTrait {
 
 E0398: r##"
 In Rust 1.3, the default object lifetime bounds are expected to change, as
-described in RFC #1156 [1]. You are getting a warning because the compiler
+described in [RFC 1156]. You are getting a warning because the compiler
 thinks it is possible that this change will cause a compilation error in your
 code. It is possible, though unlikely, that this is a false alarm.
 
@@ -1365,7 +1365,7 @@ fn foo<'a>(arg: &Box<SomeTrait+'a>) { ... }
 This explicitly states that you expect the trait object `SomeTrait` to contain
 references (with a maximum lifetime of `'a`).
 
-[1]: https://github.com/rust-lang/rfcs/pull/1156
+[RFC 1156]: https://github.com/rust-lang/rfcs/blob/master/text/1156-adjust-default-object-bounds.md
 "##,
 
 E0452: r##"
@@ -1771,6 +1771,7 @@ This pattern is incorrect because, because the type of `foo` is a function
 **item** (`typeof(foo)`), which is zero-sized, and the target type (`fn()`)
 is a function pointer, which is not zero-sized.
 This pattern should be rewritten. There are a few possible ways to do this:
+
 - change the original fn declaration to match the expected signature,
   and do the cast in the fn body (the prefered option)
 - cast the fn item fo a fn pointer before calling transmute, as shown here:

src/librustc_resolve/diagnostics.rs

@@ -890,19 +890,23 @@ match (A, B, C) {
 E0422: r##"
 You are trying to use an identifier that is either undefined or not a struct.
 Erroneous code example:
-``` compile_fail,E0422
+
+```compile_fail,E0422
 fn main () {
     let x = Foo { x: 1, y: 2 };
 }
 ```
+
 In this case, `Foo` is undefined, so it inherently isn't anything, and
 definitely not a struct.
+
 ```compile_fail
 fn main () {
     let foo = 1;
     let x = foo { x: 1, y: 2 };
 }
 ```
+
 In this case, `foo` is defined, but is not a struct, so Rust can't use it as
 one.
 "##,

src/librustc_typeck/diagnostics.rs

@@ -790,7 +790,7 @@ Furthermore, the syntax is changing to use `in` instead of `box`. See [RFC 470]
 and [RFC 809] for more details.
 
 [RFC 470]: https://github.com/rust-lang/rfcs/pull/470
-[RFC 809]: https://github.com/rust-lang/rfcs/pull/809
+[RFC 809]: https://github.com/rust-lang/rfcs/blob/master/text/0809-box-and-in-for-stdlib.md
 "##,
 
 E0067: r##"
@@ -1428,7 +1428,7 @@ type X = u32; // this compiles
 ```
 
 Note that type parameters for enum-variant constructors go after the variant,
-not after the enum (Option::None::<u32>, not Option::<u32>::None).
+not after the enum (`Option::None::<u32>`, not `Option::<u32>::None`).
 "##,
 
 E0110: r##"
@@ -1521,7 +1521,7 @@ impl Bar for u32 {
 
 For information on the design of the orphan rules, see [RFC 1023].
 
-[RFC 1023]: https://github.com/rust-lang/rfcs/pull/1023
+[RFC 1023]: https://github.com/rust-lang/rfcs/blob/master/text/1023-rebalancing-coherence.md
 "##,
 
 E0118: r##"
@@ -1911,8 +1911,9 @@ type Foo = Trait<Bar=i32>; // ok!
 
 E0192: r##"
 Negative impls are only allowed for traits with default impls. For more
-information see the [opt-in builtin traits RFC](https://github.com/rust-lang/
-rfcs/blob/master/text/0019-opt-in-builtin-traits.md).
+information see the [opt-in builtin traits RFC][RFC 19].
+
+[RFC 19]: https://github.com/rust-lang/rfcs/blob/master/text/0019-opt-in-builtin-traits.md
 "##,
 
 E0193: r##"
@@ -2147,7 +2148,7 @@ E0202: r##"
 Inherent associated types were part of [RFC 195] but are not yet implemented.
 See [the tracking issue][iss8995] for the status of this implementation.
 
-[RFC 195]: https://github.com/rust-lang/rfcs/pull/195
+[RFC 195]: https://github.com/rust-lang/rfcs/blob/master/text/0195-associated-items.md
 [iss8995]: https://github.com/rust-lang/rust/issues/8995
 "##,
 
@@ -2424,7 +2425,7 @@ such that `Ti` is a local type. Then no type parameter can appear in any of the
 
 For information on the design of the orphan rules, see [RFC 1023].
 
-[RFC 1023]: https://github.com/rust-lang/rfcs/pull/1023
+[RFC 1023]: https://github.com/rust-lang/rfcs/blob/master/text/1023-rebalancing-coherence.md
 "##,
 
 /*
@@ -2799,8 +2800,9 @@ verify this assertion; therefore we must tag this `impl` as unsafe.
 
 E0318: r##"
 Default impls for a trait must be located in the same crate where the trait was
-defined. For more information see the [opt-in builtin traits RFC](https://github
-.com/rust-lang/rfcs/blob/master/text/0019-opt-in-builtin-traits.md).
+defined. For more information see the [opt-in builtin traits RFC][RFC 19].
+
+[RFC 19]: https://github.com/rust-lang/rfcs/blob/master/text/0019-opt-in-builtin-traits.md
 "##,
 
 E0321: r##"
@@ -3018,10 +3020,8 @@ impl<T> Unsize<T> for MyType {}
 ```
 
 If you are defining your own smart pointer type and would like to enable
-conversion from a sized to an unsized type with the [DST coercion system]
-(https://github.com/rust-lang/rfcs/blob/master/text/0982-dst-coercion.md), use
-[`CoerceUnsized`](https://doc.rust-lang.org/std/ops/trait.CoerceUnsized.html)
-instead.
+conversion from a sized to an unsized type with the
+[DST coercion system][RFC 982], use [`CoerceUnsized`] instead.
 
 ```
 #![feature(coerce_unsized)]
@@ -3035,6 +3035,9 @@ pub struct MyType<T: ?Sized> {
 impl<T, U> CoerceUnsized<MyType<U>> for MyType<T>
     where T: CoerceUnsized<U> {}
 ```
+
+[RFC 982]: https://github.com/rust-lang/rfcs/blob/master/text/0982-dst-coercion.md
+[`CoerceUnsized`]: https://doc.rust-lang.org/std/ops/trait.CoerceUnsized.html
 "##,
 
 E0329: r##"
@@ -3438,8 +3441,9 @@ struct.
 
 E0380: r##"
 Default impls are only allowed for traits with no methods or associated items.
-For more information see the [opt-in builtin traits RFC](https://github.com/rust
--lang/rfcs/blob/master/text/0019-opt-in-builtin-traits.md).
+For more information see the [opt-in builtin traits RFC][RFC 19].
+
+[RFC 19]: https://github.com/rust-lang/rfcs/blob/master/text/0019-opt-in-builtin-traits.md
 "##,
 
 E0390: r##"