Move Hooks into HscEnv

compiler/GHC.hs

compiler/GHC/Data/IOEnv.hs

compiler/GHC/Driver/Env/Types.hs

compiler/GHC/Driver/Hooks.hs

compiler/GHC/Driver/Hooks.hs-boot

compiler/GHC/Driver/Main.hs

compiler/GHC/Driver/Make.hs

compiler/GHC/Driver/Pipeline.hs

compiler/GHC/Driver/Session.hs

compiler/GHC/HsToCore/Foreign/Decl.hs

compiler/GHC/Iface/Load.hs

compiler/GHC/Rename/Splice.hs

compiler/GHC/Runtime/Loader.hs

compiler/GHC/Tc/Gen/Foreign.hs

compiler/GHC/Tc/Gen/Splice.hs

compiler/GHC/Tc/Types.hs

testsuite/tests/plugins/hooks-plugin/Hooks/Plugin.hs