Remove unncesessary TryFrom and TryInto impls

src/archive.rs

@@ -1,7 +1,6 @@
 //! Creation of ar archives like for the lib and staticlib crate type
 
 use std::collections::BTreeMap;
-use std::convert::TryFrom;
 use std::fs::File;
 use std::io::{self, Read, Seek};
 use std::path::{Path, PathBuf};

src/debuginfo/object.rs

@@ -1,5 +1,3 @@
-use std::convert::{TryFrom, TryInto};
-
 use rustc_data_structures::fx::FxHashMap;
 
 use cranelift_module::FuncId;

src/lib.rs

@@ -71,8 +71,6 @@ mod value_and_place;
 mod vtable;
 
 mod prelude {
-    pub(crate) use std::convert::{TryFrom, TryInto};
-
     pub(crate) use rustc_span::{FileNameDisplayPreference, Span};
 
     pub(crate) use rustc_hir::def_id::{DefId, LOCAL_CRATE};