Embedded Interfaces in aux_files

Embedded interfaces in aux_files generate unknown embedded interface XXX errors. See below for example of the problem:

// source
import (
    alias "some.org/package/imported"
)

type Source interface {
    alias.Foreign
}

// some.org/package/imported
type Foreign interface {
    Embedded
}

type Embedded interface {}

Attempting to generate a mock will result in an unknown embedded interface Embedded. The issue is that the fileParser stores auxInterfaces underneath the package name explicitly specified in the aux_files flag.

In the parseInterface method, there is an incorrect assumption about an embedded interface always being in the source file.

case *ast.Ident:
        // Embedded interface in this package.
        ei := p.auxInterfaces[""][v.String()]
        if ei == nil {
                return nil, p.errorf(v.Pos(), "unknown embedded interface %s", v.String())
        }