Switch to purely namespaced enums

This breaks code that referred to variant names in the same namespace as
their enum. Reexport the variants in the old location or alter code to
refer to the new locations:

```
pub enum Foo {
    A,
    B
}

fn main() {
    let a = A;
}
```
=>
```
pub use self::Foo::{A, B};

pub enum Foo {
    A,
    B
}

fn main() {
    let a = A;
}
```
or
```
pub enum Foo {
    A,
    B
}

fn main() {
    let a = Foo::A;
}
```

[breaking-change]

1 files changed, 2 insertions, 0 deletions

diff --git a/src/libstd/path/windows.rs b/src/libstd/path/windows.rs
index a053f57bf12..f31ffdab17b 100644
--- a/src/libstd/path/windows.rs
+++ b/src/libstd/path/windows.rs
@@ -12,6 +12,8 @@
 
 //! Windows file path handling
 
+pub use self::PathPrefix::*;
+
 use ascii::AsciiCast;
 use c_str::{CString, ToCStr};
 use clone::Clone;