Fix using Definitions as arguments to Definitions (backport #3726) (#3731)

* Fix using Definitions as arguments to Definitions (#3726)

(cherry picked from commit a050b8cd

)

# Conflicts:
#	core/src/main/scala/chisel3/Module.scala
#	core/src/main/scala/chisel3/experimental/hierarchy/core/Definition.scala
#	core/src/main/scala/chisel3/experimental/hierarchy/core/Instance.scala
#	core/src/main/scala/chisel3/internal/Builder.scala

* Resolve backport conflicts

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Co-authored-by: Jack Koenig <koenig@sifive.com>