Plugin generation of Bundle elements is now mandatory

[jackkoenig]

Feature originally added in v3.5.1, it was technically a binary incompatible change so in v3.6.0 it will become mandatory.

This enables removing reflection.

Contributor Checklist

• [NA] 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

• performance improvement
• code cleanup

API Impact

No impact since the plugin is required and the same names are given.

Backend Code Generation Impact

No impact

Desired Merge Strategy

• Squash

Release Notes

Make Chisel-plugin generation of Bundle.elements mandatory. Scalac option -P:chiselplugin:genBundleElements no longer does anything.

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 mark as Please Merge?

[mwachs5]

rubber stamp! Exciting.