Added test case for global import all

gcc/testsuite/ChangeLog:

	* rust/compile/glob-import-all.rs: New test.

Signed-off-by: AhmedSaid3617 <said.ahmed3617@gmail.com>

Author: AhmedSaid3617

gcc/testsuite/rust/compile/glob-import-all.rs

@@ -0,0 +1,9 @@
+// { dg-additional-options "-frust-edition=2015" }
+
+#![feature(no_core)]
+#![no_core]
+
+mod a {
+    #[allow(unused)]
+    use ::*;
+}