Fix chisel3 <> for Bundles that contain compatibility Bundles (backport #2023) (#2026)

* Fix chisel3 <> for Bundles that contain compatibility Bundles (#2023)

BiConnect in chisel3 delegates to FIRRTL <- semantics whenever it hits a
Bundle defined in `import Chisel._`. Because chisel3 <> is commutative
it needs to be mindful of flippedness when emitting a FIRRTL <- (which
is *not* commutative).

(cherry picked from commit 16c0b53e

)

* Fix test issue in Scala 2.11

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