Avoid redundant imports of GHC.Driver.Session
Remove GHC.Driver.Session
imports that weren't considered as redundant
because of the reexport of PlatformConstants
. Also remove this reexport
as modules using this datatype should import GHC.Platform
instead.
And also (second commit) Reverse dependency between StgToCmm and Runtime.Heap.Layout
because it removes a layering violation in GHC.Runtime.Heap.Layout
.