Compute the size of pages before allocating memory (#14650)

`start_memory_manager()` calls `zend_mm_init()` via `alloc_globals_ctor()`
before setting `REAL_PAGE_SIZE` to the right value. Moving the `REAL_PAGE_SIZE`
setting block before the call to `alloc_globals_ctor()` makes the allocator
behave properly on systems with a page size different than 4k.

Suggested-by: arnaud-lb

Author: jvoisin

Zend/zend_alloc.c

@@ -3109,18 +3109,18 @@ static void alloc_globals_dtor(zend_alloc_globals *alloc_globals)
 
 ZEND_API void start_memory_manager(void)
 {
-#ifdef ZTS
-	ts_allocate_fast_id(&alloc_globals_id, &alloc_globals_offset, sizeof(zend_alloc_globals), (ts_allocate_ctor) alloc_globals_ctor, (ts_allocate_dtor) alloc_globals_dtor);
-#else
-	alloc_globals_ctor(&alloc_globals);
-#endif
 #ifndef _WIN32
 #  if defined(_SC_PAGESIZE)
 	REAL_PAGE_SIZE = sysconf(_SC_PAGESIZE);
 #  elif defined(_SC_PAGE_SIZE)
 	REAL_PAGE_SIZE = sysconf(_SC_PAGE_SIZE);
 #  endif
 #endif
+#ifdef ZTS
+	ts_allocate_fast_id(&alloc_globals_id, &alloc_globals_offset, sizeof(zend_alloc_globals), (ts_allocate_ctor) alloc_globals_ctor, (ts_allocate_dtor) alloc_globals_dtor);
+#else
+	alloc_globals_ctor(&alloc_globals);
+#endif
 }
 
 ZEND_API zend_mm_heap *zend_mm_set_heap(zend_mm_heap *new_heap)