gh-144319: Use transparent huge pages via madvise(MADV_HUGEPAGE) in pymalloc (#144353)

Author: maurycy

Objects/obmalloc.c

@@ -665,6 +665,9 @@ _PyMem_ArenaAlloc(void *Py_UNUSED(ctx), size_t size)
     if (ptr == MAP_FAILED)
         return NULL;
     assert(ptr != NULL);
+#ifdef MADV_HUGEPAGE
+    (void)madvise(ptr, size, MADV_HUGEPAGE);
+#endif
     (void)_PyAnnotateMemoryMap(ptr, size, "cpython:pymalloc");
     return ptr;
 #else