fix message

Author: TaKO8Ki

compiler/rustc_resolve/src/lib.rs

@@ -2527,7 +2527,7 @@ impl<'a> Resolver<'a> {
                                     Some((
                                         vec![],
                                         String::from(
-                                            "add `extern crate alloc` to use the builtin `alloc` module",
+                                            "add `extern crate alloc` to use the `alloc` crate",
                                         ),
                                         Applicability::MaybeIncorrect,
                                     ))

src/test/ui/suggestions/undeclared-module-alloc.stderr

@@ -4,7 +4,7 @@ error[E0433]: failed to resolve: use of undeclared crate or module `alloc`
 LL | use alloc::rc::Rc;
    |     ^^^^^ use of undeclared crate or module `alloc`
    |
-   = help: add `extern crate alloc` to use the builtin `alloc` module
+   = help: add `extern crate alloc` to use the `alloc` crate
 
 error: aborting due to previous error