[Instantiate] Do not fail on function pointers

src/plugins/instantiate/Makefile.in

@@ -62,7 +62,7 @@ PLUGIN_CMO := \
 PLUGIN_DISTRIBUTED := $(PLUGIN_ENABLE)
 PLUGIN_DISTRIB_EXTERNAL:= Makefile.in configure.ac configure
 #PLUGIN_NO_DEFAULT_TEST := no
-PLUGIN_TESTS_DIRS := string stdlib options api
+PLUGIN_TESTS_DIRS := string stdlib options api plugin
 
 ################
 # Generic part #

src/plugins/instantiate/tests/plugin/function_pointers.i

+/* run.config
+  OPT: -instantiate
+*/
+void foo(void (* bar)()){
+  (*bar)();
+}
\ No newline at end of file

src/plugins/instantiate/tests/plugin/oracle/function_pointers.res.oracle

+[kernel] Parsing tests/plugin/function_pointers.i (no preprocessing)

src/plugins/instantiate/transform.ml

@@ -104,7 +104,8 @@ class transformer = object(self)
     | Not_found -> (fct, args)
 
   method! vinst = function
-    | Call(_) | Local_init(_, ConsInit(_, _, Plain_func), _) ->
+    | Call(_, { enode = Lval((Var _), NoOffset)} , _, _)
+    | Local_init(_, ConsInit(_ , _, Plain_func), _) ->
       let change = function
         | [ Call(r, ({ enode = Lval((Var f), NoOffset) } as e), args, loc) ] ->
           let f, args = self#replace_call (r, f, args) in