Remove the lifetime from `DiagnosticArgValue`.

Because it's almost always static.

This makes `impl IntoDiagnosticArg for DiagnosticArgValue` trivial,
which is nice.

There are a few diagnostics constructed in
`compiler/rustc_mir_build/src/check_unsafety.rs` and
`compiler/rustc_mir_transform/src/errors.rs` that now need symbols
converted to `String` with `to_string` instead of `&str` with `as_str`,
but that' no big deal, and worth it for the simplifications elsewhere.

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 0743ff03864..9788fcb3c7d 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -90,7 +90,7 @@ impl PatternSource {
 }
 
 impl IntoDiagnosticArg for PatternSource {
-    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue {
         DiagnosticArgValue::Str(Cow::Borrowed(self.descr()))
     }
 }