[TargetPassConfig] Don't add alias analysis at optnone

When performing codegen at optnone, don't add alias analysis to
the pipeline. We don't need it, but it causes an unnecessary
dominator tree calculation.

I've also moved the module verifier call to the top so that a bunch
of disabled-at-optnone passes group more nicely.

Differential Revision: https://reviews.llvm.org/D80378