Fix compilation errors in Linq.fs for wp7 target

src/fsharp/FSharp.Core/Linq.fs

@@ -781,7 +781,10 @@ module LeafExpressionConverter =
     // provides no other way to evaluate the expression.
     //
     // REVIEW: It is possible it is just better to interpret the expression in many common cases, e.g. property-gets, values etc.
-    let EvaluateQuotation (e: Microsoft.FSharp.Quotations.Expr) = 
+    let EvaluateQuotation (e: Microsoft.FSharp.Quotations.Expr) : obj = 
+#if FX_NO_QUOTATIONS_COMPILE
+       raise (new NotSupportedException())
+#else
        match e with
        | Value (obj,_) -> obj
        | _ -> 
@@ -793,7 +796,7 @@ module LeafExpressionConverter =
            d.DynamicInvoke [| box () |]
        with :? System.Reflection.TargetInvocationException as exn -> 
            raise exn.InnerException
-
+#endif
 
 #endif
-
+