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.

3 files changed, 5 insertions, 5 deletions

diff --git a/compiler/rustc_codegen_ssa/src/assert_module_sources.rs b/compiler/rustc_codegen_ssa/src/assert_module_sources.rs
index a1daadce958..ad5a74b04e4 100644
--- a/compiler/rustc_codegen_ssa/src/assert_module_sources.rs
+++ b/compiler/rustc_codegen_ssa/src/assert_module_sources.rs
@@ -206,7 +206,7 @@ impl fmt::Display for CguReuse {
 }
 
 impl IntoDiagnosticArg for CguReuse {
-    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue {
         DiagnosticArgValue::Str(Cow::Owned(self.to_string()))
     }
 }
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index b13d566b40b..affd386361c 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -999,7 +999,7 @@ type DiagnosticArgName<'source> = Cow<'source, str>;
 
 struct Diagnostic {
     msgs: Vec<(DiagnosticMessage, Style)>,
-    args: FxHashMap<DiagnosticArgName<'static>, rustc_errors::DiagnosticArgValue<'static>>,
+    args: FxHashMap<DiagnosticArgName<'static>, rustc_errors::DiagnosticArgValue>,
     code: Option<ErrCode>,
     lvl: Level,
 }
@@ -1811,7 +1811,7 @@ impl Translate for SharedEmitter {
 
 impl Emitter for SharedEmitter {
     fn emit_diagnostic(&mut self, diag: &rustc_errors::Diagnostic) {
-        let args: FxHashMap<Cow<'_, str>, rustc_errors::DiagnosticArgValue<'_>> =
+        let args: FxHashMap<Cow<'_, str>, rustc_errors::DiagnosticArgValue> =
             diag.args().map(|(name, arg)| (name.clone(), arg.clone())).collect();
         drop(self.sender.send(SharedEmitterMessage::Diagnostic(Diagnostic {
             msgs: diag.messages.clone(),
diff --git a/compiler/rustc_codegen_ssa/src/errors.rs b/compiler/rustc_codegen_ssa/src/errors.rs
index ef291ead190..06ea5b9e8f4 100644
--- a/compiler/rustc_codegen_ssa/src/errors.rs
+++ b/compiler/rustc_codegen_ssa/src/errors.rs
@@ -147,7 +147,7 @@ impl<'a> CopyPath<'a> {
 struct DebugArgPath<'a>(pub &'a Path);
 
 impl IntoDiagnosticArg for DebugArgPath<'_> {
-    fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> {
+    fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue {
         DiagnosticArgValue::Str(Cow::Owned(format!("{:?}", self.0)))
     }
 }
@@ -974,7 +974,7 @@ pub enum ExpectedPointerMutability {
 }
 
 impl IntoDiagnosticArg for ExpectedPointerMutability {
-    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue {
         match self {
             ExpectedPointerMutability::Mut => DiagnosticArgValue::Str(Cow::Borrowed("*mut")),
             ExpectedPointerMutability::Not => DiagnosticArgValue::Str(Cow::Borrowed("*_")),