Rollup merge of #121085 - davidtwco:always-eager-diagnostics, r=nnethercote

errors: only eagerly translate subdiagnostics

Subdiagnostics don't need to be lazily translated, they can always be eagerly translated. Eager translation is slightly more complex as we need to have a `DiagCtxt` available to perform the translation, which involves slightly more threading of that context.

This slight increase in complexity should enable later simplifications - like passing `DiagCtxt` into `AddToDiagnostic` and moving Fluent messages into the diagnostic structs rather than having them in separate files (working on that was what led to this change).

r? ```@nnethercote```

1 files changed, 5 insertions, 2 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 7de13bf0c02..0472981086e 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -4558,11 +4558,14 @@ fn hint_missing_borrow<'tcx>(
     }
 
     if !to_borrow.is_empty() {
-        err.subdiagnostic(errors::AdjustSignatureBorrow::Borrow { to_borrow });
+        err.subdiagnostic(infcx.dcx(), errors::AdjustSignatureBorrow::Borrow { to_borrow });
     }
 
     if !remove_borrow.is_empty() {
-        err.subdiagnostic(errors::AdjustSignatureBorrow::RemoveBorrow { remove_borrow });
+        err.subdiagnostic(
+            infcx.dcx(),
+            errors::AdjustSignatureBorrow::RemoveBorrow { remove_borrow },
+        );
     }
 }