bpo-46670: Remove unused macros in ceval.c (GH-31196)

Remove CHECKEXC() and EXT_POP() macros.

Python/ceval.c

@@ -40,9 +40,8 @@
 #include <stdbool.h>
 
 #ifdef Py_DEBUG
-/* For debugging the interpreter: */
-#define LLTRACE  1      /* Low-level trace feature */
-#define CHECKEXC 1      /* Double-check exception checking */
+   /* For debugging the interpreter: */
+#  define LLTRACE  1      /* Low-level trace feature */
 #endif
 
 #if !defined(Py_BUILD_CORE)
@@ -1456,15 +1455,11 @@ eval_frame_handle_pending(PyThreadState *tstate)
                             (void)(BASIC_STACKADJ(-(n))); \
                             assert(STACK_LEVEL() <= frame->f_code->co_stacksize); \
                         } while (0)
-#define EXT_POP(STACK_POINTER) ((void)(lltrace && \
-                                prtrace(tstate, (STACK_POINTER)[-1], "ext_pop")), \
-                                *--(STACK_POINTER))
 #else
 #define PUSH(v)                BASIC_PUSH(v)
 #define POP()                  BASIC_POP()
 #define STACK_GROW(n)          BASIC_STACKADJ(n)
 #define STACK_SHRINK(n)        BASIC_STACKADJ(-(n))
-#define EXT_POP(STACK_POINTER) (*--(STACK_POINTER))
 #endif
 
 /* Local variable macros */