Transcribe the Compiler Lecture Representing types in rustc

[spastorino]

Video: https://www.youtube.com/watch?v=c01TsOsr3-c

This issue has been assigned to @igaray via this comment.

[spastorino]

@rustbot assign @igaray

[mark-i-m]

@spastorino Is this a duplicate of #348?

[spastorino]

Yes, this is the issue, #348 is the PR.