Auto merge of #111671 - Dylan-DPC:rollup-1jy5r16, r=Dylan-DPC

Rollup of 6 pull requests

Successful merges:

 - #110145 (Share slice of bytes)
 - #111043 (Stabilize feature `cstr_is_empty`)
 - #111648 (Remove `LangItems::require`)
 - #111649 (Add derive for `core::marker::ConstParamTy`)
 - #111654 (Add a conversion from `&mut T` to `&mut UnsafeCell<T>`)
 - #111661 (Erase regions of type in `offset_of!`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

compiler/rustc_middle/src/error.rs

@@ -1,5 +1,5 @@
 use rustc_macros::Diagnostic;
-use rustc_span::Span;
+use rustc_span::{Span, Symbol};
 
 use crate::ty::Ty;
 
@@ -73,6 +73,14 @@ pub(crate) struct StrictCoherenceNeedsNegativeCoherence {
     pub attr_span: Option<Span>,
 }
 
+#[derive(Diagnostic)]
+#[diag(middle_requires_lang_item)]
+pub(crate) struct RequiresLangItem {
+    #[primary_span]
+    pub span: Option<Span>,
+    pub name: Symbol,
+}
+
 #[derive(Diagnostic)]
 #[diag(middle_const_not_used_in_type_alias)]
 pub(super) struct ConstNotUsedTraitAlias {

compiler/rustc_middle/src/middle/lang_items.rs

@@ -18,12 +18,8 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Returns the `DefId` for a given `LangItem`.
     /// If not found, fatally aborts compilation.
     pub fn require_lang_item(self, lang_item: LangItem, span: Option<Span>) -> DefId {
-        self.lang_items().require(lang_item).unwrap_or_else(|err| {
-            if let Some(span) = span {
-                self.sess.span_fatal(span, err.to_string())
-            } else {
-                self.sess.fatal(err.to_string())
-            }
+        self.lang_items().get(lang_item).unwrap_or_else(|| {
+            self.sess.emit_fatal(crate::error::RequiresLangItem { span, name: lang_item.name() });
         })
     }