[COMMITTED 117/144] gccrs: Add box definition to avoid error

[arthur.cohen@embecosm.com]

From: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>

Box definition is part of the standard library and cannot be found during
name resolution. This simple definition prevent any error from being
emitted.

gcc/testsuite/ChangeLog:

	* rust/compile/box_syntax_feature_gate.rs: Add box land item
	definition.

Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>
---
 gcc/testsuite/rust/compile/box_syntax_feature_gate.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gcc/testsuite/rust/compile/box_syntax_feature_gate.rs b/gcc/testsuite/rust/compile/box_syntax_feature_gate.rs
index 8eb5503dde6..5f62a59a04b 100644
--- a/gcc/testsuite/rust/compile/box_syntax_feature_gate.rs
+++ b/gcc/testsuite/rust/compile/box_syntax_feature_gate.rs
@@ -1,4 +1,6 @@
 // { dg-options "-frust-compile-until=lowering" }
+#[lang = "owned_box"]
+pub struct Box<T>;
 
 fn main() {
     let x: Box<_> = box 1; //{ dg-error "box expression syntax is experimental." "" { target *-*-* }  }
-- 
2.45.2