Fix #716: OverflowException when converting System.Enum To System.Int64 in CustomAttribute

ICSharpCode.Decompiler/Ast/AstBuilder.cs

@@ -1521,7 +1521,8 @@ namespace ICSharpCode.Decompiler.Ast
 			}
 			var type = argument.Type.Resolve();
 			if (type != null && type.IsEnum) {
-				return MakePrimitive(Convert.ToInt64(argument.Value), type);
+				long val = (long)CSharpPrimitiveCast.Cast(TypeCode.Int64, argument.Value, false);
+				return MakePrimitive(val, type);
 			} else if (argument.Value is TypeReference) {
 				return CreateTypeOfExpression((TypeReference)argument.Value);
 			} else {

ICSharpCode.Decompiler/Tests/CustomAttributes/S_CustomAttributes.cs

@@ -39,6 +39,11 @@ namespace aa
 			{
 			}
 		}
+		[CustomAttributes.MyAttribute(CustomAttributes.ULongEnum.MaxUInt64)]
+		public enum ULongEnum : ulong
+		{
+			MaxUInt64 = 18446744073709551615uL
+		}
 		[CustomAttributes.MyAttribute(CustomAttributes.EnumWithFlag.Item1 | CustomAttributes.EnumWithFlag.Item2)]
 		private static int field;
 		[CustomAttributes.MyAttribute(CustomAttributes.EnumWithFlag.All)]

NRefactory.VB/ICSharpCode.NRefactory.VB.Tests/ICSharpCode.NRefactory.VB.Tests.csproj

@@ -102,5 +102,8 @@
       <Name>ICSharpCode.NRefactory</Name>
     </ProjectReference>
   </ItemGroup>
+  <ItemGroup>
+    <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
+  </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSHARP.Targets" />
 </Project>