Switch the default -dynload mode to SystemDependent

The previous default was Deployable though it was being
overridden to Wrapper in the ghc shell script wrapper.

compiler/main/DynFlags.hs

@@ -614,7 +614,7 @@ defaultDynFlags =
 
         outputFile              = Nothing,
         outputHi                = Nothing,
-        dynLibLoader            = Deployable,
+        dynLibLoader            = SystemDependent,
         dumpPrefix              = Nothing,
         dumpPrefixForce         = Nothing,
         includePaths            = [],

ghc/ghc.wrapper

-exec $executablename -B$datadir -dynload wrapped ${1+"$@"}
+exec $executablename -B$datadir ${1+"$@"}