lint: port explicit outlives diagnostics

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

Author: davidtwco

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

@@ -376,3 +376,9 @@ lint-builtin-unnameable-test-items = cannot test inner items
 
 lint-builtin-keyword-idents = `{$kw}` is a keyword in the {$next} edition
     .suggestion = you can use a raw identifier to stay compatible
+
+lint-builtin-explicit-outlives = outlives requirements can be inferred
+    .suggestion = remove {$count ->
+        [one] this bound
+        *[other] these bounds
+    }

compiler/rustc_lint/src/builtin.rs

@@ -2288,13 +2288,10 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements {
 
             if !lint_spans.is_empty() {
                 cx.struct_span_lint(EXPLICIT_OUTLIVES_REQUIREMENTS, lint_spans.clone(), |lint| {
-                    lint.build("outlives requirements can be inferred")
+                    lint.build(fluent::lint::builtin_explicit_outlives)
+                        .set_arg("count", bound_count)
                         .multipart_suggestion(
-                            if bound_count == 1 {
-                                "remove this bound"
-                            } else {
-                                "remove these bounds"
-                            },
+                            fluent::lint::suggestion,
                             lint_spans
                                 .into_iter()
                                 .map(|span| (span, String::new()))