Remove LLVM_TARGET platform macros

Instead following @angerman's suggestion put them in the config file.
Maybe we could re-key llvm-targets someday, but this is good for now.

compiler/ghc.mk

@@ -109,7 +109,6 @@ compiler/stage1/$(PLATFORM_H) : mk/config.mk mk/project.mk | $$(dir $$@)/.
 	@echo "#define BUILD_ARCH \"$(BuildArch_CPP)\""           >> $@
 	@echo "#define HOST_ARCH \"$(HostArch_CPP)\""             >> $@
 	@echo "#define TARGET_ARCH \"$(TargetArch_CPP)\""         >> $@
-	@echo "#define LLVM_TARGET \"$(LLVMTarget_CPP)\""         >> $@
 	@echo                                                     >> $@
 	@echo "#define $(BuildOS_CPP)_BUILD_OS 1"                 >> $@
 	@echo "#define $(HostOS_CPP)_HOST_OS 1"                   >> $@
@@ -150,7 +149,6 @@ compiler/stage2/$(PLATFORM_H) : mk/config.mk mk/project.mk | $$(dir $$@)/.
 	@echo "#define BUILD_ARCH \"$(HostArch_CPP)\""            >> $@
 	@echo "#define HOST_ARCH \"$(TargetArch_CPP)\""           >> $@
 	@echo "#define TARGET_ARCH \"$(TargetArch_CPP)\""         >> $@
-	@echo "#define LLVM_TARGET \"$(LLVMTarget_CPP)\""         >> $@
 	@echo                                                     >> $@
 	@echo "#define $(HostOS_CPP)_BUILD_OS 1"                  >> $@
 	@echo "#define $(TargetOS_CPP)_HOST_OS 1"                 >> $@

compiler/llvmGen/LlvmCodeGen.hs

@@ -90,7 +90,7 @@ llvmCodeGen' cmm_stream
   where
     header :: SDoc
     header = sdocWithDynFlags $ \dflags ->
-      let target = LLVM_TARGET
+      let target = platformMisc_llvmTarget $ platformMisc dflags
           layout = case lookup target (llvmTargets dflags) of
             Just (LlvmTarget dl _ _) -> dl
             Nothing -> error $ "Failed to lookup the datalayout for " ++ target ++ "; available targets: " ++ show (map fst $ llvmTargets dflags)

compiler/main/DriverPipeline.hs

@@ -867,7 +867,7 @@ llvmOptions dflags =
                                  , not (any (isInfixOf "-mcpu") (getOpts dflags opt_lc)) ]
     ++ [("", "-mattr=" ++ attrs) | not (null attrs) ]
 
-  where target = LLVM_TARGET
+  where target = platformMisc_llvmTarget $ platformMisc dflags
         Just (LlvmTarget _ mcpu mattr) = lookup target (llvmTargets dflags)
 
         -- Relocation models

compiler/main/SysTools.hs

@@ -236,6 +236,8 @@ initSysTools top_dir
              ld_prog  = cc_prog
              ld_args  = map Option (cc_args ++ words cc_link_args_str)
 
+       llvmTarget <- getSetting "LLVM target"
+
        -- We just assume on command line
        lc_prog <- getSetting "LLVM llc command"
        lo_prog <- getSetting "LLVM opt command"
@@ -336,6 +338,7 @@ initSysTools top_dir
            , platformMisc_ghcThreaded = ghcThreaded
            , platformMisc_ghcDebugged = ghcDebugged
            , platformMisc_ghcRtsWithLibdw = ghcRtsWithLibdw
+           , platformMisc_llvmTarget = llvmTarget
            }
 
          , sPlatformConstants = platformConstants

hadrian/src/Rules/Generate.hs

@@ -307,6 +307,7 @@ generateSettings = do
         , ("target has subsections via symbols", expr $ lookupValueOrError configFile "haskell-have-subsections-via-symbols")
         , ("target has RTS linker", expr $ lookupValueOrError configFile "haskell-have-rts-linker")
         , ("Unregisterised", expr $ yesNo <$> flag GhcUnregisterised)
+        , ("LLVM target", getSetting LlvmTarget)
         , ("LLVM llc command", expr $ settingsFileSetting SettingsFileSetting_LlcCommand)
         , ("LLVM opt command", expr $ settingsFileSetting SettingsFileSetting_OptCommand)
         , ("LLVM clang command", expr $ settingsFileSetting SettingsFileSetting_ClangCommand)
@@ -413,7 +414,6 @@ generateGhcBootPlatformH = do
     hostVendor     <- chooseSetting HostVendor    TargetVendor
     targetPlatform <- getSetting TargetPlatform
     targetArch     <- getSetting TargetArch
-    llvmTarget     <- getSetting LlvmTarget
     targetOs       <- getSetting TargetOs
     targetVendor   <- getSetting TargetVendor
     return $ unlines
@@ -433,7 +433,6 @@ generateGhcBootPlatformH = do
         , "#define BUILD_ARCH "  ++ show buildArch
         , "#define HOST_ARCH "   ++ show hostArch
         , "#define TARGET_ARCH " ++ show targetArch
-        , "#define LLVM_TARGET " ++ show llvmTarget
         , ""
         , "#define " ++ buildOs  ++ "_BUILD_OS 1"
         , "#define " ++ hostOs   ++ "_HOST_OS 1"

includes/ghc.mk

@@ -209,6 +209,7 @@ $(includes_SETTINGS) : includes/Makefile | $$(dir $$@)/.
 	@echo ',("target has subsections via symbols", "$(HaskellHaveSubsectionsViaSymbols)")' >> $@
 	@echo ',("target has RTS linker", "$(HaskellHaveRTSLinker)")' >> $@
 	@echo ',("Unregisterised", "$(Unregisterised)")' >> $@
+	@echo ',("LLVM target", "$(LLVMTarget_CPP)")' >> $@
 	@echo ',("LLVM llc command", "$(SettingsLlcCommand)")' >> $@
 	@echo ',("LLVM opt command", "$(SettingsOptCommand)")' >> $@
 	@echo ',("LLVM clang command", "$(SettingsClangCommand)")' >> $@

libraries/ghc-boot/GHC/Platform.hs

@@ -243,6 +243,7 @@ data PlatformMisc = PlatformMisc
   , platformMisc_ghcThreaded          :: Bool
   , platformMisc_ghcDebugged          :: Bool
   , platformMisc_ghcRtsWithLibdw      :: Bool
+  , platformMisc_llvmTarget           :: String
   }
 
 data IntegerLibrary