gccrs: Adds tests from issue 4245

Adds tests for the testsuite

gcc/testsuite/ChangeLog:

	* rust/compile/issue-4245.rs: New test.

Signed-off-by: lenny.chiadmi-delage <[email protected]>

Author: Villosse

gcc/testsuite/rust/compile/issue-4245.rs

@@ -0,0 +1,10 @@
+#![cfg_attr(not(cg_gcc), feature(intrinsics))]
+#![feature(lang_items)]
+
+#[lang = "sized"]
+pub trait Sized {}
+
+#[cfg(not(cg_gcc))]
+extern "rust-intrinsic" {
+    fn copy_nonoverlapping<T>(src: &T, dst: &mut T, count: usize);
+}