[nem-en] Bugs in extension method implementation

[vc]

   > Well it works for me in simple examples:
   > 
   > tlib.n:
   > public module Extend {
   >   public Reverse['a] (this a : array ['a]) : void {
   >     System.Array.Reverse (a);
   >   }
   > }
   > 
   > t.n:
   > def f (a : array [int]) {
   >   a.Reverse ();
   > }
   > 
   > def a = array [1,2,3];
   > f (a);
   
   Try (in reference you need add Nemerle.Compiler.dll):
   using System.Console;
   using Nemerle.Compiler;
   
   def member : IMember = null;
   WriteLine(member.GetName())
   
   You get this error message:
   Main.n(5,11,5,25): error : there is no member named `GetName' in
Nemerle.Compiler.IMember with type ?
    
   > So it is probably some other issue. I don't remember if there was any
   > fresh bootstrap in boot/ since I fixed this bug, maybe this is the
   > reason?
   
   Hardly, as I compile this code by not bootstrap compiler. And the
Reflector shows, that in assembly all ОК.
   
   I find error with the help of debugger. It source a different assemble
modules (with same version) of Nemerle.dll loaded by compiler. In this case
IsDefined() method report false even if in type exist ExtensionAttribute.
   
   I have changed logic of determination of presence the ExtensionAttribute.
   Now it finde simply by name. See ncc\external\LibrariesLoader.n line 391:
   public static IsExtension (attrsProvider :
System.Reflection.ICustomAttributeProvider) : bool
   {
     def attrs = attrsProvider.GetCustomAttributes(false);
     NArray.Exists(attrs, attr => attr.GetType().Name ==
"ExtensionAttribute")
   }
   It's the same way as support LINQ ExtensionAttribute and any
ExtensionAttribute defined in any assembly.
   
   PS
   
   Check this solution and if it's OK, update bootstrap, please.