Use plugin dict to store introspector

manticore/core/manticore.py

@@ -1196,8 +1196,9 @@ def introspect(self) -> typing.Dict[int, StateDescriptor]:
 
         :return: the latest copy of the State Descriptor dict
         """
-        if self._introspector is not None:
-            return self._introspector.get_state_descriptors()
+        key = IntrospectionAPIPlugin.NAME
+        if key in self.plugins:
+            return self.plugins[key].get_state_descriptors()
         return {}
 
     @at_not_running

manticore/core/plugin.py

@@ -465,6 +465,8 @@ class IntrospectionAPIPlugin(Plugin):
     and stores them in its context, and keeps them up to date whenever a callback registers a change in the State.
     """
 
+    NAME = "introspector"
+
     def create_state(self, state_id: int):
         """
         Adds a StateDescriptor to the context in the READY state list
@@ -665,3 +667,6 @@ def get_state_descriptors(self) -> typing.Dict[int, StateDescriptor]:
         with self.locked_context("manticore_state", dict) as context:
             out = context.copy()  # TODO: is this necessary to break out of the lock?
         return out
+
+    def unique_name(self) -> str:
+        return IntrospectionAPIPlugin.NAME