Revert "Altered RFC to allow super-trait imports."

This reverts commit 98834a4.

Author: obsgolem

text/0000-import-trait-methods.md

@@ -53,7 +53,7 @@ Importing a method from a trait does not import the trait. If you want to call `
 
 ```rust
 mod a {
-    pub trait A {
+    trait A {
         fn new() -> Self;
         fn do_something(&self);
     }
@@ -97,10 +97,10 @@ impl S {
 }
 ```
 
-You can also import a parent trait method from a sub-trait:
+You cannot import a parent trait method from a sub-trait:
 
 ```rust
-use num_traits::float::Float::zero;
+use num_traits::float::Float::zero; // Error: try `use num_traits::identities::Zero::zero` instead.
 
 fn main() {
     let x : f64 = zero();
@@ -116,10 +116,7 @@ When
 ```rust
 use Trait::method as m;
 ```
-occurs, we first find the supertrait in which `method` occurs. If it occurs in multiple supertraits, or in the trait and in a supertrait, then error.
-A new item `m` is made available in the function namespace of the current module. Any attempts to call this item are treated calling the (super-)trait method explicitly qualified. As always, the `as` qualifier is optional, in which case the name of the new item is identical with the name of the method in the trait. 
-
-In other words, the example:
+occurs, a new item `m` is made available in the function namespace of the current module. Any attempts to call this item are treated calling the trait method explicitly qualified. As always, the `as` qualifier is optional, in which case the name of the new item is identical with the name of the method in the trait. In other words, the example:
 
 ```rust
 use Default::default;
@@ -169,26 +166,7 @@ is sugar for
 use some_module::Trait;
 ```
 
-Finally, given traits 
-```rust
-trait Super {
-    fn f();
-}
-
-trait Sub : Super {
-}
-```
-the usage
-```rust
-use module::Sub::f;
-f();
-```
-desugars to
-```rust
-use module::Sub::f;
-Super::f();
-```
-**not** `Sub::f();` as that desugaring will cause compiler errors, see https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=51bef9ba69ce1fc20248e987bf106bd4.
+The restriction on importing parent trait methods is a consequence of this desugaring, see https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=51bef9ba69ce1fc20248e987bf106bd4 for examples of the errors you get when you try to call parent trait methods through a child trait. We will likely want better error messages than this if a user tries to import a parent method.
 
 # Drawbacks
 [drawbacks]: #drawbacks
@@ -219,8 +197,6 @@ In [Zulip](https://rust-lang.zulipchat.com/#narrow/stream/213817-t-lang/topic/Wr
 
 Option 1 is what is proposed here. It has the simplest semantics, and I believe it best matches the user intent when they import a trait method; the desire is to make that method available as-if it were a regular function. Furthermore, it is more minimalist than the other two options in the sense that you can get to option 2 simply by importing the trait also. Option 3 seems like extra complexity for almost no added value.
 
-An earlier version of this RFC proposed not allowing `use Trait::super_trait_method`. This was changed because comments indicated this usecase would be common.
-
 ## What is the impact of not doing this?
 
 Users of the language continue to create helper methods to access trait methods with regular function syntax. More specifically, each such instance requires a minimum of three lines when using normal rust formatting, corresponding to the following example: