Add a test for enum variant name resolution

Highlight the fact that a value inside an enum definition refers to
a struct outside of the enum and not to the enum variant's name
directly.

gcc/testsuite/ChangeLog:

	* rust/compile/enum_variant_name.rs: New test.

Signed-off-by: Pierre-Emmanuel Patry <[email protected]>

Author: P-E-P

gcc/testsuite/rust/compile/enum_variant_name.rs

@@ -0,0 +1,12 @@
+// { dg-additional-options "-w -frust-name-resolution-2.0" }
+struct E1;
+
+enum Test {
+    E1 = {
+        let x = E1;
+        {
+            let x = E1;
+        }
+        0
+    },
+}