ghc-heap: remove wrong Addr# coercion (#23181)

Conversion from Addr# to I# isn't correct with the JS backend.

libraries/ghc-heap/GHC/Exts/Heap.hs

@@ -120,7 +120,7 @@ instance Word64# ~ a => HasHeapRep (a :: TYPE 'Word64Rep) where
 
 instance Addr# ~ a => HasHeapRep (a :: TYPE 'AddrRep) where
     getClosureData x = return $
-        AddrClosure { ptipe = PAddr, addrVal = I# (unsafeCoerce# x) }
+        AddrClosure { ptipe = PAddr, addrVal = Ptr x }
 
 instance Float# ~ a => HasHeapRep (a :: TYPE 'FloatRep) where
     getClosureData x = return $

libraries/ghc-heap/GHC/Exts/Heap/Closures.hs

@@ -329,7 +329,7 @@ data GenClosure b
     -- | Primitive Addr
   | AddrClosure
         { ptipe      :: PrimType
-        , addrVal    :: !Int }
+        , addrVal    :: !(Ptr ()) }
 
     -- | Primitive Float
   | FloatClosure

libraries/ghc-heap/tests/heap_all.hs

@@ -12,6 +12,7 @@ import GHC.Int
 import GHC.IO
 import GHC.IORef
 import GHC.MVar
+import GHC.Ptr
 import GHC.Stack
 import GHC.STRef
 import GHC.Weak
@@ -176,7 +177,7 @@ exWord64Closure = Word64Closure
 
 exAddrClosure :: Closure
 exAddrClosure = AddrClosure
-    { ptipe = PAddr, addrVal = 42 }
+    { ptipe = PAddr, addrVal = nullPtr `plusPtr` 42 }
 
 exFloatClosure :: Closure
 exFloatClosure = FloatClosure
@@ -328,7 +329,7 @@ main = do
     --     assertClosuresEq exWord64Closure
 
     -- Primitive Addr
-    let v = unsafeCoerce# 42# :: Addr#
+    let (Ptr v) = nullPtr `plusPtr` 42
     getClosureData v >>=
         assertClosuresEq exAddrClosure