support remote_build_history with optional ghc_setup / ocaml_setup;

--- a/src/Pure/Admin/build_history.scala	Mon Nov 05 20:53:16 2018 +0100
+++ b/src/Pure/Admin/build_history.scala	Mon Nov 05 21:59:22 2018 +0100
@@ -513,6 +513,8 @@
     progress: Progress = No_Progress,
     rev: String = "",
     afp_rev: Option[String] = None,
+    ghc_setup: Boolean = false,
+    ocaml_setup: Boolean = false,
     options: String = "",
     args: String = ""): List[(String, Bytes)] =
   {
@@ -537,6 +539,10 @@
       execute("bin/isabelle", "components -I")
       execute("bin/isabelle", "components -a", echo = true)
       execute("Admin/build", "jars_fresh")
+      for {
+        (setup, tool) <- List((ghc_setup, "ghc_setup"), (ocaml_setup, "ocaml_setup"))
+        if setup && ssh.is_file(Path.explode("lib/Tools/" + tool))
+      } execute("bin/isabelle", tool, echo = true)
     }
 
     val rev_id = self_hg.id(rev)

--- a/src/Pure/Admin/isabelle_cronjob.scala	Mon Nov 05 20:53:16 2018 +0100
+++ b/src/Pure/Admin/isabelle_cronjob.scala	Mon Nov 05 21:59:22 2018 +0100
@@ -159,6 +159,8 @@
     historic: Boolean = false,
     history: Int = 0,
     history_base: String = "build_history_base",
+    ghc_setup: Boolean = false,
+    ocaml_setup: Boolean = false,
     options: String = "",
     args: String = "",
     afp: Boolean = false,
@@ -345,6 +347,8 @@
                 self_update = r.self_update,
                 rev = rev,
                 afp_rev = afp_rev,
+                ghc_setup = r.ghc_setup,
+                ocaml_setup = r.ocaml_setup,
                 options =
                   " -N " + Bash.string(task_name) + (if (i < 0) "" else "_" + (i + 1).toString) +
                   " -f " + r.options,