[COMMITTED 5/9] gccrs: Add testcase for #[rustc_const_stable]

[arthur . cohen]

From: Arthur Cohen <arthur.co...@embecosm.com>

To ensure we don't introduce regressions back to issue #2314

gcc/testsuite/ChangeLog:

        * rust/compile/rustc_const_stable.rs: New test.
---
 gcc/testsuite/rust/compile/rustc_const_stable.rs | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 gcc/testsuite/rust/compile/rustc_const_stable.rs

diff --git a/gcc/testsuite/rust/compile/rustc_const_stable.rs 
b/gcc/testsuite/rust/compile/rustc_const_stable.rs
new file mode 100644
index 00000000000..9208b1ab3b6
--- /dev/null
+++ b/gcc/testsuite/rust/compile/rustc_const_stable.rs
@@ -0,0 +1,2 @@
+#[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = 
"1.47.0")]
+pub fn foo() {} // { dg-error "macro not found" "" { target *-*-* } .-1 }
-- 
2.42.1