Fixes in method signature generator (#51)

***NO_CI***

Author: josesimoes

source/MetadataProcessor.Core/Tables/nanoByteCodeTable.cs

@@ -62,7 +62,7 @@ public nanoByteCodeTable(
         public ushort NextMethodId { get { return (ushort)_methods.Count; } }
 
         /// <summary>
-        /// Temporary string table for code generators used duing initial load.
+        /// Temporary string table for code generators used during initial load.
         /// </summary>
         public nanoStringTable FakeStringTable { get { return _fakeStringTable; } }
 

source/MetadataProcessor.Core/Tables/nanoSignaturesTable.cs

@@ -66,8 +66,8 @@ static nanoSignaturesTable()
             PrimitiveTypes.Add(typeof(bool).FullName, nanoCLR_DataType.DATATYPE_BOOLEAN);
 
             PrimitiveTypes.Add(typeof(object).FullName, nanoCLR_DataType.DATATYPE_OBJECT);
-            PrimitiveTypes.Add(typeof(IntPtr).FullName, nanoCLR_DataType.DATATYPE_VALUETYPE);
-            //PrimitiveTypes.Add(typeof(UIntPtr).FullName, nanoCLR_DataType.DATATYPE_U4);
+            PrimitiveTypes.Add(typeof(IntPtr).FullName, nanoCLR_DataType.DATATYPE_I4);
+            PrimitiveTypes.Add(typeof(UIntPtr).FullName, nanoCLR_DataType.DATATYPE_U4);
 
             PrimitiveTypes.Add("System.WeakReference", nanoCLR_DataType.DATATYPE_WEAKCLASS);
         }