[gcc/devel/rust/master] derive(Clone): Mark PhantomData as a lang item

[Thomas Schwinge]

https://gcc.gnu.org/g:533abf7e53c6edb699d67418a84b662bd41cf381

commit 533abf7e53c6edb699d67418a84b662bd41cf381
Author: Arthur Cohen <arthur.cohen@embecosm.com>
Date:   Thu Dec 26 10:57:07 2024 +0000

    derive(Clone): Mark PhantomData as a lang item
    
    gcc/testsuite/ChangeLog:
    
            * rust/compile/derive_macro4.rs: Make PhantomData a lang item.

Diff:
---
 gcc/testsuite/rust/compile/derive_macro4.rs | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/gcc/testsuite/rust/compile/derive_macro4.rs b/gcc/testsuite/rust/compile/derive_macro4.rs
index 7802e8fd8000..b20043ba927b 100644
--- a/gcc/testsuite/rust/compile/derive_macro4.rs
+++ b/gcc/testsuite/rust/compile/derive_macro4.rs
@@ -6,12 +6,9 @@ pub trait Clone {
     fn clone(&self) -> Self;
 }
 
+#[lang = "phantom_data"]
 struct PhantomData<T>;
 
-pub struct AssertParamIsCopy<T: Copy> {
-    _field: PhantomData<T>,
-}
-
 #[derive(Clone)] // { dg-error "bounds not satisfied for U .Copy. is not satisfied" }
 union U {
     i: i32,