Support Compact Framework 3.5
diff --git a/src/ProtocolBuffers/CodedOutputStream.cs b/src/ProtocolBuffers/CodedOutputStream.cs
index bb5e6a2..a7e1eca 100644
--- a/src/ProtocolBuffers/CodedOutputStream.cs
+++ b/src/ProtocolBuffers/CodedOutputStream.cs
@@ -332,7 +332,7 @@
     /// </summary>
     public void WriteDoubleNoTag(double value) {
       // TODO(jonskeet): Test this on different endiannesses
-#if SILVERLIGHT2
+#if SILVERLIGHT2 || COMPACT_FRAMEWORK_35
       byte[] bytes = BitConverter.GetBytes(value);
       WriteRawBytes(bytes, 0, 8);
 #else
@@ -1140,4 +1140,4 @@
       }
     }
   }
-}
\ No newline at end of file
+}