Hoopl: remove dependency on Hoopl package

This copies the subset of Hoopl's functionality needed by GHC to
`cmm/Hoopl` and removes the dependency on the Hoopl package.

The main motivation for this change is the confusing/noisy interface
between GHC and Hoopl:
- Hoopl has `Label` which is GHC's `BlockId` but different than
  GHC's `CLabel`
- Hoopl has `Unique` which is different than GHC's `Unique`
- Hoopl has `Unique{Map,Set}` which are different than GHC's
  `Uniq{FM,Set}`
- GHC has its own specialized copy of `Dataflow`, so `cmm/Hoopl` is
  needed just to filter the exposed functions (filter out some of the
  Hoopl's and add the GHC ones)
With this change, we'll be able to simplify this significantly.
It'll also be much easier to do invasive changes (Hoopl is a public
package on Hackage with users that depend on the current behavior)

This should introduce no changes in functionality - it merely
copies the relevant code.

Signed-off-by: Michal Terepeta <michal.terepeta@gmail.com>

Test Plan: ./validate

Reviewers: austin, bgamari, simonmar

Reviewed By: bgamari, simonmar

Subscribers: simonpj, kavon, rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D3616

3 files changed, 4 insertions, 3 deletions

diff --git a/compiler/codeGen/CgUtils.hs b/compiler/codeGen/CgUtils.hs
index d8f268d2bd..7184153f10 100644
--- a/compiler/codeGen/CgUtils.hs
+++ b/compiler/codeGen/CgUtils.hs
@@ -14,7 +14,8 @@ module CgUtils ( fixStgRegisters ) where
 
 import CodeGen.Platform
 import Cmm
-import Hoopl
+import Hoopl.Block
+import Hoopl.Graph
 import CmmUtils
 import CLabel
 import DynFlags
diff --git a/compiler/codeGen/StgCmmHeap.hs b/compiler/codeGen/StgCmmHeap.hs
index a0b822dfd6..db62985e3c 100644
--- a/compiler/codeGen/StgCmmHeap.hs
+++ b/compiler/codeGen/StgCmmHeap.hs
@@ -36,7 +36,7 @@ import StgCmmEnv
 
 import MkGraph
 
-import Hoopl
+import Hoopl.Label
 import SMRep
 import BlockId
 import Cmm
diff --git a/compiler/codeGen/StgCmmMonad.hs b/compiler/codeGen/StgCmmMonad.hs
index 754cbfb19e..5e62183fb5 100644
--- a/compiler/codeGen/StgCmmMonad.hs
+++ b/compiler/codeGen/StgCmmMonad.hs
@@ -64,7 +64,7 @@ module StgCmmMonad (
 import Cmm
 import StgCmmClosure
 import DynFlags
-import Hoopl
+import Hoopl.Collections
 import Maybes
 import MkGraph
 import BlockId