CSESubAccesses was intended to be a simple workaround for a quadratic
performance bug in RemoveAccesses but ended up having tricky corner
cases and was hard to get right. The solution to the RemoveAccesses
bug--quadratic expansion of dynamic indexes of vecs of aggreate
type--turned out to be quite simple and makes CSESubAccesses much less
useful and not worth fixing.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

* scalatest: replace deprecated FlatSpec and add new Matchers import

* scalatest: 3.1.2 -> 3.2.1

* InferTypesFlowsAndKindsSpec: test the results of InferTypes, ResolveKinds and ResolveFlows

* Don't use passes sub-package in tests

This changes two test files using the "passes" sub-package to
"firrtl.passes". This allows a new "firrtlTests.passes" package to be
freely created and used without a name collision.

Signed-off-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>

* ResolveFlows: only depends on types and working ir

The types are needed to know the orientation of
a bundle field of a SubField node.

* InferTypes: fix bugs with unknown widths on ports and memories

* LoweringCompileSpec: Uniquify pass moved

Co-authored-by: Schuyler Eldridge <schuyler.eldridge@ibm.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>