Add _PyCode_GetVarCounts().

Author: ericsnowcurrently

Include/internal/pycore_code.h

@@ -564,6 +564,49 @@ extern int _Py_ClearUnusedTLBC(PyInterpreterState *interp);
 #endif
 
 
+typedef struct {
+    int total;
+    struct co_locals_counts {
+        int total;
+        struct {
+            int total;
+            int numposonly;
+            int numposorkw;
+            int numkwonly;
+            int varargs;
+            int varkwargs;
+        } args;
+        int numpure;
+        struct {
+            int total;
+            // numargs does not contribute to locals.total.
+            int numargs;
+            int numothers;
+        } cells;
+        struct {
+            int total;
+            int numpure;
+            int numcells;
+        } hidden;
+    } locals;
+    int numfree;  // nonlocal
+    struct co_unbound_counts {
+        int total;
+        int numglobal;
+        int numattrs;
+        int numunknown;
+    } unbound;
+} _PyCode_var_counts_t;
+
+PyAPI_FUNC(void) _PyCode_GetVarCounts(
+        PyCodeObject *,
+        _PyCode_var_counts_t *);
+PyAPI_FUNC(int) _PyCode_SetUnboundVarCounts(
+        PyCodeObject *,
+        _PyCode_var_counts_t *,
+        PyObject *global,
+        PyObject *attrs);
+
 PyAPI_FUNC(int) _PyCode_ReturnsOnlyNone(PyCodeObject *);