Use the "main" transform-interpreter pass instead of the test pass.
This, along with the previously introduced debug extension, now allow
tutorials to no longer depend on test passes and extensions.
The transform dialect has been around for a while and is sufficiently
stable at this point. Add the first three chapters of the tutorial
describing its usage and extension.
Reviewed By: springerm
Differential Revision: https://reviews.llvm.org/D151491