bpo-35064 prefix smelly symbols that appear with COUNT_ALLOCS with _Py_ (GH-10152)

Configuring python with ./configure --with-pydebug CFLAGS="-D COUNT_ALLOCS -O0"
makes "make smelly" fail as some symbols were being exported without the "Py_" or
"_Py" prefixes.
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index ec39500..f1579c7 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -929,7 +929,7 @@
 
 
 #ifdef COUNT_ALLOCS
-extern void dump_counts(FILE*);
+extern void _Py_dump_counts(FILE*);
 #endif
 
 /* Flush stdout and stderr */
@@ -1112,7 +1112,7 @@
 
     /* Debugging stuff */
 #ifdef COUNT_ALLOCS
-    dump_counts(stderr);
+    _Py_dump_counts(stderr);
 #endif
     /* dump hash stats */
     _PyHash_Fini();