[serialization] Print the path to a too-new, too-old, or malformed module file.

<rdar://problem/16680615>

Swift SVN r16637

include/swift/Serialization/SerializedModuleLoader.h

@@ -41,7 +41,10 @@ enum class ModuleStatus {
   MissingShadowedModule,
 
   /// The module file is malformed in some way.
-  Malformed
+  Malformed,
+
+  /// The module documentation file is malformed in some way.
+  MalformedDocumentation
 };
 
 /// \brief Imports serialized Swift modules into an ASTContext.