FindExportData positions the reader r at the beginning of the export data section of an underlying GC-created object/archive file by reading from it.

FindPkg returns the filename and unique package id for an import path based on package information provided by build.Import (using the build.Default build.Context).

Import imports a gc-generated package given its import path, adds the corresponding package object to the packages map, and returns the object.

ImportData imports a package by reading the gc-generated export data, adds the corresponding package object to the packages map indexed by id, and returns the object.