bpo-40268: Include explicitly pycore_interp.h (GH-19505)

pycore_pystate.h no longer includes pycore_interp.h:
it's now included explicitly in files accessing PyInterpreterState.
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index 1820d8c..7cb72ce 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -5,7 +5,8 @@
 #include "opcode.h"
 #include "structmember.h"
 #include "pycore_code.h"
-#include "pycore_pystate.h"
+#include "pycore_interp.h"        // PyInterpreterState.co_extra_freefuncs
+#include "pycore_pystate.h"       // _PyInterpreterState_GET_UNSAFE()
 #include "pycore_tupleobject.h"
 #include "clinic/codeobject.c.h"
 
diff --git a/Objects/interpreteridobject.c b/Objects/interpreteridobject.c
index 3f31687..84fd858 100644
--- a/Objects/interpreteridobject.c
+++ b/Objects/interpreteridobject.c
@@ -2,6 +2,7 @@
 
 #include "Python.h"
 #include "pycore_abstract.h"   // _PyIndex_Check()
+#include "pycore_interp.h"     // _PyInterpreterState_LookUpID()
 #include "pycore_pystate.h"
 #include "interpreteridobject.h"
 
diff --git a/Objects/longobject.c b/Objects/longobject.c
index a66e1c4..a0bb6bc 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -3,7 +3,8 @@
 /* XXX The functional organization of this file is terrible */
 
 #include "Python.h"
-#include "pycore_pystate.h"   /* _Py_IsMainInterpreter() */
+#include "pycore_interp.h"    // _PY_NSMALLPOSINTS
+#include "pycore_pystate.h"   // _Py_IsMainInterpreter()
 #include "longintrepr.h"
 
 #include <float.h>
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 30adc92..acb920a 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -2,6 +2,7 @@
 /* Module object implementation */
 
 #include "Python.h"
+#include "pycore_interp.h"    // PyInterpreterState.importlib
 #include "pycore_pystate.h"
 #include "structmember.h"