Add translatable diagnostic for cannot find in this scope

compiler/rustc_resolve/messages.ftl

@@ -267,4 +267,7 @@ resolve_change_import_binding =
     you can use `as` to change the binding name of the import
 
 resolve_imports_cannot_refer_to =
-    imports cannot refer to {$what}
+    imports cannot refer to {$what}
+
+resolve_cannot_find_ident_in_this_scope =
+    cannot find {$expected} `{$ident}` in this scope

compiler/rustc_resolve/src/errors.rs

@@ -613,3 +613,12 @@ pub(crate) struct ImportsCannotReferTo<'a> {
     pub(crate) span: Span,
     pub(crate) what: &'a str,
 }
+
+#[derive(Diagnostic)]
+#[diag(resolve_cannot_find_ident_in_this_scope)]
+pub(crate) struct CannotFindIdentInThisScope<'a> {
+    #[primary_span]
+    pub(crate) span: Span,
+    pub(crate) expected: &'a str,
+    pub(crate) ident: Ident,
+}

compiler/rustc_resolve/src/macros.rs

@@ -1,7 +1,9 @@
 //! A bunch of methods and structures more or less related to resolving macros and
 //! interface provided by `Resolver` to macro expander.
 
-use crate::errors::{self, AddAsNonDerive, MacroExpectedFound, RemoveSurroundingDerive};
+use crate::errors::{
+    self, AddAsNonDerive, CannotFindIdentInThisScope, MacroExpectedFound, RemoveSurroundingDerive,
+};
 use crate::Namespace::*;
 use crate::{BuiltinMacroState, Determinacy};
 use crate::{DeriveData, Finalize, ParentScope, ResolutionError, Resolver, ScopeSet};
@@ -793,8 +795,13 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 }
                 Err(..) => {
                     let expected = kind.descr_expected();
-                    let msg = format!("cannot find {} `{}` in this scope", expected, ident);
+
-                    let mut err = self.tcx.sess.struct_span_err(ident.span, msg);
+                    let mut err = self.tcx.sess.create_err(CannotFindIdentInThisScope {
+                        span: ident.span,
+                        expected,
+                        ident,
+                    });
+
                     self.unresolved_macro_suggestions(&mut err, kind, &parent_scope, ident, krate);
                     err.emit();
                 }