[gcc r17-2231] gccrs: Add testcases to show gat issue is fixed

https://gcc.gnu.org/g:af7e7defb63bb05b8ba619f6b55730b8a1643c75

commit r17-2231-gaf7e7defb63bb05b8ba619f6b55730b8a1643c75
Author: Philip Herron <[email protected]>
Date:   Wed Jun 24 15:37:42 2026 +0100

    gccrs: Add testcases to show gat issue is fixed
    
    Fixes Rust-GCC#4471
    
    gcc/testsuite/ChangeLog:
    
            * rust/compile/issue-4471-1.rs: New test.
            * rust/compile/issue-4471-2.rs: New test.
    
    Signed-off-by: Philip Herron <[email protected]>

Diff:
---
 gcc/testsuite/rust/compile/issue-4471-1.rs | 10 ++++++++++
 gcc/testsuite/rust/compile/issue-4471-2.rs | 28 ++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/gcc/testsuite/rust/compile/issue-4471-1.rs b/gcc/testsuite/rust/compile/issue-4471-1.rs
new file mode 100644
index 000000000000..9b06b8c6b8e4
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-4471-1.rs
@@ -0,0 +1,10 @@
+#![feature(no_core, intrinsics, staged_api, lang_items)]
+#![no_core]
+
+#[lang = "sized"]
+pub trait Sized {}
+
+trait Foo<T> {}
+trait Bar: Foo {} // { dg-error {generic item takes at least 1 type arguments but 0 were supplied \[E0107\]} }
+impl<T> Bar for T {}
+impl Foo<i32> for i32 {}
diff --git a/gcc/testsuite/rust/compile/issue-4471-2.rs b/gcc/testsuite/rust/compile/issue-4471-2.rs
new file mode 100644
index 000000000000..75db746f1c95
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-4471-2.rs
@@ -0,0 +1,28 @@
+#![feature(no_core, intrinsics, staged_api, lang_items)]
+#![no_core]
+
+#[lang = "sized"]
+pub trait Sized {}
+
+trait Foo<T> {
+    fn get(&self) -> T;
+}
+
+trait Bar: Foo<i32> + Foo { // { dg-error {generic item takes at least 1 type arguments but 0 were supplied \[E0107\]} }
+    fn double_get(&self) -> i32 {
+        self.get() + self.get()
+    }
+}
+
+impl<T> Bar for T where T: Foo<i32> {}
+
+impl Foo<i32> for i32 {
+    fn get(&self) -> i32 {
+        *self
+    }
+}
+
+fn main() {
+    let x: i32 = 1;
+    Bar::double_get(&x);
+}