lint: port incomplete features diagnostics

Signed-off-by: David Wood <david.wood@huawei.com>

Author: davidtwco

compiler/rustc_error_messages/locales/en-US/lint.ftl

@@ -382,3 +382,7 @@ lint-builtin-explicit-outlives = outlives requirements can be inferred
         [one] this bound
         *[other] these bounds
     }
+
+lint-builtin-incomplete-features = the feature `{$name}` is incomplete and may not be safe to use and/or cause compiler crashes
+    .note = see issue #{$n} <https://github.com/rust-lang/rust/issues/{$n}> for more information
+    .help = consider using `min_{$name}` instead, which is more stable and complete

compiler/rustc_errors/src/diagnostic.rs

@@ -115,6 +115,12 @@ impl IntoDiagnosticArg for String {
     }
 }
 
+impl IntoDiagnosticArg for std::num::NonZeroU32 {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        DiagnosticArgValue::Str(Cow::Owned(self.to_string()))
+    }
+}
+
 impl IntoDiagnosticArg for Edition {
     fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
         DiagnosticArgValue::Str(Cow::Owned(self.to_string()))

compiler/rustc_lint/src/builtin.rs

@@ -2347,23 +2347,14 @@ impl EarlyLintPass for IncompleteFeatures {
             .filter(|(&name, _)| features.incomplete(name))
             .for_each(|(&name, &span)| {
                 cx.struct_span_lint(INCOMPLETE_FEATURES, span, |lint| {
-                    let mut builder = lint.build(&format!(
-                        "the feature `{}` is incomplete and may not be safe to use \
-                         and/or cause compiler crashes",
-                        name,
-                    ));
+                    let mut builder = lint.build(fluent::lint::builtin_incomplete_features);
+                    builder.set_arg("name", name);
                     if let Some(n) = rustc_feature::find_feature_issue(name, GateIssue::Language) {
-                        builder.note(&format!(
-                            "see issue #{} <https://github.com/rust-lang/rust/issues/{}> \
-                             for more information",
-                            n, n,
-                        ));
+                        builder.set_arg("n", n);
+                        builder.note(fluent::lint::note);
                     }
                     if HAS_MIN_FEATURES.contains(&name) {
-                        builder.help(&format!(
-                            "consider using `min_{}` instead, which is more stable and complete",
-                            name,
-                        ));
+                        builder.help(fluent::lint::help);
                     }
                     builder.emit();
                 })