Fix Nested Instantiate (#4018)

* minimal reproduce Nested Instantiate bug

* expose cache and elaborated defination to inner defination

* fix up

(cherry picked from commit 02b01e8b)

# Conflicts:
#	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
#	src/main/scala/chisel3/aop/injecting/InjectingAspect.scala
#	src/main/scala/chisel3/stage/phases/Elaborate.scala
#	src/test/scala/chiselTests/experimental/hierarchy/InstantiateSpec.scala