Rollup merge of #105537 - kadiwa4:remove_some_imports, r=fee1-dead

compiler: remove unnecessary imports and qualified paths

Some of these imports were necessary before Edition 2021, others were already in the prelude.

I hope it's fine that this PR is so spread-out across files :/

3 files changed, 1 insertions, 3 deletions

diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
index 4d80f904ac4..74a0c13b23f 100644
--- a/compiler/rustc_ast/src/ast.rs
+++ b/compiler/rustc_ast/src/ast.rs
@@ -33,7 +33,6 @@ use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 use rustc_span::source_map::{respan, Spanned};
 use rustc_span::symbol::{kw, sym, Ident, Symbol};
 use rustc_span::{Span, DUMMY_SP};
-use std::convert::TryFrom;
 use std::fmt;
 use std::mem;
 use thin_vec::{thin_vec, ThinVec};
diff --git a/compiler/rustc_ast/src/ptr.rs b/compiler/rustc_ast/src/ptr.rs
index 30481eddf91..4b2850336a0 100644
--- a/compiler/rustc_ast/src/ptr.rs
+++ b/compiler/rustc_ast/src/ptr.rs
@@ -22,7 +22,6 @@
 //!   Moreover, a switch to, e.g., `P<'a, T>` would be easy and mostly automated.
 
 use std::fmt::{self, Debug, Display};
-use std::iter::FromIterator;
 use std::ops::{Deref, DerefMut};
 use std::{slice, vec};
 
diff --git a/compiler/rustc_ast/src/tokenstream.rs b/compiler/rustc_ast/src/tokenstream.rs
index 482c302950f..29a5eb4b7c5 100644
--- a/compiler/rustc_ast/src/tokenstream.rs
+++ b/compiler/rustc_ast/src/tokenstream.rs
@@ -362,7 +362,7 @@ impl TokenStream {
     }
 }
 
-impl iter::FromIterator<TokenTree> for TokenStream {
+impl FromIterator<TokenTree> for TokenStream {
     fn from_iter<I: IntoIterator<Item = TokenTree>>(iter: I) -> Self {
         TokenStream::new(iter.into_iter().collect::<Vec<TokenTree>>())
     }