google/traceur-compiler — pull request #639 by johnjbarton (2014-01-06 23:08:25+00:00)
Title: ModuleDescription:Module :: ModuleSymbol:Tree

To allow pre-compiled modules to mix with demand-loaded
modules we invent ModuleDescription with a subset of
the ModuleSymbol API. When we analyze exports we can read
but not write on the ModuleDescription objects.