diff --git a/compiler/CodeGen.Platform.h b/compiler/CodeGen.Platform.h
--- a/compiler/CodeGen.Platform.h
+++ b/compiler/CodeGen.Platform.h
@@ -926,6 +926,14 @@
 -- ip0 -- used for spill offset computations
 freeReg 16 = False
 
+#if defined(darwin_HOST_OS) || defined(ios_HOST_OS)
+-- x18 is reserved by the platform on Darwin/iOS, and can not be used
+-- More about ARM64 ABI that Apple platforms support:
+-- https://developer.apple.com/documentation/xcode/writing-arm64-code-for-apple-platforms
+-- https://github.com/Siguza/ios-resources/blob/master/bits/arm64.md
+freeReg 18 = False
+#endif
+
 # if defined(REG_Base)
 freeReg REG_Base  = False
 # endif
diff --git a/compiler/GHC/Driver/Pipeline/Monad.hs b/compiler/GHC/Driver/Pipeline/Monad.hs
--- a/compiler/GHC/Driver/Pipeline/Monad.hs
+++ b/compiler/GHC/Driver/Pipeline/Monad.hs
@@ -29,6 +29,7 @@
        src_filename :: String,      -- ^ basename of original input source
        src_basename :: String,      -- ^ basename of original input source
        src_suffix   :: String,      -- ^ its extension
+       start_phase  :: Phase,
        output_spec  :: PipelineOutput -- ^ says where to put the pipeline output
   }
 
diff --git a/compiler/GHC/Stg/InferTags/TagSig.hs b/compiler/GHC/Stg/InferTags/TagSig.hs
--- a/compiler/GHC/Stg/InferTags/TagSig.hs
+++ b/compiler/GHC/Stg/InferTags/TagSig.hs
@@ -16,6 +16,7 @@
 import GHC.Utils.Outputable
 import GHC.Utils.Binary
 import GHC.Utils.Panic.Plain
+import Data.Coerce
 
 data TagInfo
   = TagDunno            -- We don't know anything about the tag.
@@ -64,3 +65,12 @@
 isTaggedSig (TagSig TagProper) = True
 isTaggedSig (TagSig TagTagged) = True
 isTaggedSig _ = False
+
+seqTagSig :: TagSig -> ()
+seqTagSig = coerce seqTagInfo
+
+seqTagInfo :: TagInfo -> ()
+seqTagInfo TagTagged      = ()
+seqTagInfo TagDunno       = ()
+seqTagInfo TagProper      = ()
+seqTagInfo (TagTuple tis) = foldl' (\_unit sig -> seqTagSig (coerce sig)) () tis
diff --git a/compiler/GHC/StgToCmm/Types.hs b/compiler/GHC/StgToCmm/Types.hs
--- a/compiler/GHC/StgToCmm/Types.hs
+++ b/compiler/GHC/StgToCmm/Types.hs
@@ -1,7 +1,7 @@
 
 
 module GHC.StgToCmm.Types
-  ( CgInfos (..)
+  ( CmmCgInfos (..)
   , LambdaFormInfo (..)
   , ModuleLFInfos
   , StandardFormInfo (..)
@@ -13,8 +13,6 @@
 
 import GHC.Core.DataCon
 
-import GHC.Stg.InferTags.TagSig
-
 import GHC.Runtime.Heap.Layout
 
 import GHC.Types.Basic
@@ -85,7 +83,7 @@
 --
 -- See also Note [Conveying CAF-info and LFInfo between modules] above.
 --
-data CgInfos = CgInfos
+data CmmCgInfos = CmmCgInfos
   { cgNonCafs :: !NonCaffySet
       -- ^ Exported Non-CAFFY closures in the current module. Everything else is
       -- either not exported of CAFFY.
@@ -93,7 +91,6 @@
       -- ^ LambdaFormInfos of exported closures in the current module.
   , cgIPEStub :: !CStub
       -- ^ The C stub which is used for IPE information
-  , cgTagSigs :: !(NameEnv TagSig)
   }
 
 --------------------------------------------------------------------------------
diff --git a/compiler/GHC/Types/Name/Set.hs b/compiler/GHC/Types/Name/Set.hs
--- a/compiler/GHC/Types/Name/Set.hs
+++ b/compiler/GHC/Types/Name/Set.hs
@@ -220,5 +220,5 @@
 
 -- | 'Id's which have no CAF references. This is a result of analysis of C--.
 -- It is always safe to use an empty 'NonCaffySet'. TODO Refer to Note.
-newtype NonCaffySet = NonCaffySet NameSet
+newtype NonCaffySet = NonCaffySet { ncs_nameSet :: NameSet }
   deriving (Semigroup, Monoid)
diff --git a/ghc-lib-parser.cabal b/ghc-lib-parser.cabal
--- a/ghc-lib-parser.cabal
+++ b/ghc-lib-parser.cabal
@@ -1,7 +1,7 @@
 cabal-version: 2.0
 build-type: Simple
 name: ghc-lib-parser
-version: 9.4.1.20220807
+version: 9.4.2.20220822
 license: BSD3
 license-file: LICENSE
 category: Development
diff --git a/ghc-lib/stage0/libraries/ghc-boot/build/GHC/Version.hs b/ghc-lib/stage0/libraries/ghc-boot/build/GHC/Version.hs
--- a/ghc-lib/stage0/libraries/ghc-boot/build/GHC/Version.hs
+++ b/ghc-lib/stage0/libraries/ghc-boot/build/GHC/Version.hs
@@ -3,19 +3,19 @@
 import Prelude -- See Note [Why do we import Prelude here?]
 
 cProjectGitCommitId   :: String
-cProjectGitCommitId   = "6d01245c458c49ca25c89ec13be3268ab6930a27"
+cProjectGitCommitId   = "e8a889a7fc670532a3bf883a3e25acba92e6e6e1"
 
 cProjectVersion       :: String
-cProjectVersion       = "9.4.1"
+cProjectVersion       = "9.4.2"
 
 cProjectVersionInt    :: String
 cProjectVersionInt    = "904"
 
 cProjectPatchLevel    :: String
-cProjectPatchLevel    = "1"
+cProjectPatchLevel    = "2"
 
 cProjectPatchLevel1   :: String
-cProjectPatchLevel1   = "1"
+cProjectPatchLevel1   = "2"
 
 cProjectPatchLevel2   :: String
 cProjectPatchLevel2   = "0"
diff --git a/libraries/ghci/GHCi/Message.hs b/libraries/ghci/GHCi/Message.hs
--- a/libraries/ghci/GHCi/Message.hs
+++ b/libraries/ghci/GHCi/Message.hs
@@ -465,7 +465,7 @@
 #define MIN_VERSION_ghc_heap(major1,major2,minor) (\
   (major1) <  9 || \
   (major1) == 9 && (major2) <  4 || \
-  (major1) == 9 && (major2) == 4 && (minor) <= 1)
+  (major1) == 9 && (major2) == 4 && (minor) <= 2)
 #endif /* MIN_VERSION_ghc_heap */
 #if MIN_VERSION_ghc_heap(8,11,0)
 instance Binary Heap.StgTSOProfInfo