Patch Mono.Cecil to allow safe multi-threaded read access.

Mono.Cecil/Mono.Cecil/ModuleDefinition.cs

@@ -758,8 +758,11 @@ namespace Mono.Cecil {
 			return Read (this, (_, reader) => reader.LookupToken (token));
 		}
 		
+		readonly object module_lock = new object();
+
 		internal TRet Read<TItem, TRet> (TItem item, Func<TItem, MetadataReader, TRet> read)
 		{
+			lock (module_lock) {
 				var position = reader.position;
 				var context = reader.context;
 
@@ -770,6 +773,7 @@ namespace Mono.Cecil {
 
 				return ret;
 			}
+		}
 
 		void ProcessDebugHeader ()
 		{