[kernel] add test case for orphan emitter

tests/misc/oracle/orphan_emitter.res.oracle

+[kernel] Warning: emitter emitter1: correctness parameter -orphan does not exist anymore. Ignored.
+[kernel] Warning: 11 states in saved file ignored. They are invalid in this Frama-C configuration.

tests/misc/oracle/orphan_emitter_sav.res

+[kernel] Parsing orphan_emitter.i (no preprocessing)

tests/misc/orphan_emitter.i

+/* run.config
+ PLUGIN: @EVA_PLUGINS@
+ MODULE: @PTEST_NAME@
+   EXECNOW: BIN @PTEST_NAME@.sav LOG @PTEST_NAME@_sav.res LOG @PTEST_NAME@_sav.err @frama-c@ @PTEST_FILE@ -save @PTEST_NAME@.sav > @PTEST_NAME@_sav.res 2> @PTEST_NAME@_sav.err
+ MODULE:
+ COMMENT: the CMD line below omits @PTEST_FILE@ on purpose (due to -load)
+ CMD: @frama-c@ @PTEST_OPTIONS@
+   OPT: -load %{dep:@PTEST_NAME@.sav} -eva -eva-verbose 0
+*/
+int main() {
+  return 0;
+}

tests/misc/orphan_emitter.ml

+module P =
+  Plugin.Register
+    (struct
+      let name = "Orphan"
+      let shortname = "orphan"
+      let help = ""
+     end)
+
+module S =
+  P.True(struct let option_name = "-orphan" let help = "" end)
+
+let emitter1 =
+  Emitter.create "emitter1" [ Emitter.Code_annot ]
+    ~correctness:[ S.parameter ] ~tuning:[]
+
+let main () =
+  let kf = Globals.Functions.find_by_name "main" in
+  let stmt = Kernel_function.find_first_stmt kf in
+  Annotations.add_assert emitter1 stmt Logic_const.ptrue
+
+let () = Db.Main.extend main