Add DataMirror isIO, isReg, isWire

[zyedidia]

Contributor Checklist

• Did you add Scaladoc to every public function/method?
• Did you add at least one test demonstrating the PR?
• Did you delete any extraneous printlns/debugging code?
• Did you specify the type of improvement?
• Did you add appropriate documentation in docs/src?
• Did you state the API impact?
• Did you specify the code generation impact?
• Did you request a desired merge strategy?
• Did you add text to be included in the Release Notes for this change?

Type of Improvement

• new feature/API

API Impact

This extends the current DataMirror API.

Backend Code Generation Impact

Backend code generation is not changed.

Desired Merge Strategy

Squash

Release Notes

Added DataMirror methods isIO, isReg, isWire for determining the binding of a Chisel type.

Reviewer Checklist (only modified by reviewer)

• Did you add the appropriate labels?
• Did you mark the proper milestone (Bug fix: 3.4.x, [small] API extension: 3.5.x, API modification or big change: 3.6.0)?
• Did you review?
• Did you check whether all relevant Contributor checkboxes have been checked?
• Did you do one of the following when ready to merge:
  • Squash: You/ the contributor Enable auto-merge (squash), clean up the commit message, and label with Please Merge.
  • Merge: Ensure that contributor has cleaned up their commit history, then merge with Create a merge commit.

[CLAassistant]

All committers have signed the CLA.

[mwachs5]

should there be cases here for aggregate wires, regs?

[jackkoenig]

Yes it would be good to check Aggregates (Bundle and Vec) and child members of those aggregates

[zyedidia]

I updated the test to have more cases, let me know if it's still missing some desirable cases.

[jackkoenig]

CI failed because you need to run formatting via sbt scalafmtAll

[jackkoenig]

Generally looks good, just a couple of suggestions.

[jackkoenig]

LGTM! Nice work!