[mcs] Populate referencecontainer member-cache correctly. Fixes #60860

Author: marek-safar

mcs/mcs/expression.cs

@@ -9905,7 +9905,7 @@ public override bool HasConditionalAccess ()
 		public static bool IsValidDotExpression (TypeSpec type)
 		{
 			const MemberKind dot_kinds = MemberKind.Class | MemberKind.Struct | MemberKind.Delegate | MemberKind.Enum |
-				MemberKind.Interface | MemberKind.TypeParameter | MemberKind.ArrayType;
+				MemberKind.Interface | MemberKind.TypeParameter | MemberKind.ArrayType  | MemberKind.ByRef;
 
 			return (type.Kind & dot_kinds) != 0 || type.BuiltinType == BuiltinTypeSpec.Type.Dynamic;
 		}

mcs/mcs/typespec.cs

@@ -2001,6 +2001,7 @@ class ReferenceContainer : ElementTypeSpec
 		ReferenceContainer (TypeSpec element)
 			: base (MemberKind.ByRef, element, null)
 		{
+			cache = null;
 		}
 
 		public override IList<TypeSpec> Interfaces {
@@ -2041,6 +2042,11 @@ public static ReferenceContainer MakeType (ModuleContainer module, TypeSpec elem
 
 			return pc;
 		}
+
+		protected override void InitializeMemberCache(bool onlyTypes)
+		{
+			cache = Element.MemberCache;
+		}
 	}
 
 	class PointerContainer : ElementTypeSpec

mcs/tests/known-issues-interp-net_4_x

@@ -19,3 +19,4 @@ test-704.cs
 test-811.cs
 test-async-17.cs
 test-ref-08.cs IGNORE
+test-ref-09.cs IGNORE

mcs/tests/test-ref-09.cs

@@ -0,0 +1,12 @@
+struct rigidbody { public float x; }
+
+class Program
+{
+	static rigidbody a;
+	static ref rigidbody property_returning_struct_by_ref => ref a;
+
+	static void Main()
+	{
+		System.Console.WriteLine (property_returning_struct_by_ref.x);
+	}
+}

mcs/tests/ver-il-net_4_x.xml

@@ -72967,6 +72967,19 @@
       </method>
     </type>
   </test>
+  <test name="test-ref-09.cs">
+    <type name="Program">
+      <method name="rigidbody&amp; get_property_returning_struct_by_ref()" attrs="2193">
+        <size>13</size>
+      </method>
+      <method name="Void Main()" attrs="145">
+        <size>17</size>
+      </method>
+      <method name="Void .ctor()" attrs="6278">
+        <size>7</size>
+      </method>
+    </type>
+  </test>
   <test name="test-static-using-01.cs">
     <type name="A.B.X">
       <method name="Int32 Test()" attrs="150">