auto merge of #17163 : pcwalton/rust/impls-next-to-struct, r=alexcrichton

type they provide an implementation for.

This breaks code like:

    mod foo {
        struct Foo { ... }
    }

    impl foo::Foo {
        ...
    }

Change this code to:

    mod foo {
        struct Foo { ... }

        impl Foo {
            ...
        }
    }

Closes #17059.

RFC #155.

[breaking-change]

r? @brson

src/libsyntax/parse/parser.rs

@@ -82,6 +82,7 @@ use ptr::P;
 use owned_slice::OwnedSlice;
 
 use std::collections::HashSet;
+use std::io::fs::PathExtensions;
 use std::mem::replace;
 use std::mem;
 use std::rc::Rc;