added failing test, repro confirmed #4921

Author: retailcoder

RubberduckTests/Inspections/ParameterCanBeByValInspectionTests.cs

@@ -1575,6 +1575,30 @@ Private Sub abc_Foo(ByRef arg1 As Integer, ByRef arg2 As Integer)
             }
         }
 
+        [Test]
+        [Category("Inspections")]
+        public void ParameterCanBeByVal_EnumMemberParameterCanBeByVal()
+        {
+            //Input
+            const string inputCode = @"Option Explicit
+Public Enum TestEnum
+    Foo
+    Bar
+End Enum
+
+Private Sub DoSomething(e As TestEnum)
+    Debug.Print e
+End Sub";
+
+            var vbe = MockVbeBuilder.BuildFromSingleStandardModule(inputCode, out _);
+            using (var state = MockParser.CreateAndParse(vbe.Object))
+            {
+                var inspection = new ParameterCanBeByValInspection(state);
+                var inspectionResults = inspection.GetInspectionResults(CancellationToken.None);
+
+                Assert.AreEqual("e", inspectionResults.Single().Target.IdentifierName);
+            }
+        }
         [Test]
         [Category("Inspections")]
         public void InspectionName()