lib/alloc/, lib/, src/, tests/: Organize the allocation APIs in a new subdirectory

Signed-off-by: Alejandro Colomar <alx@kernel.org>

lib/alloc/reallocf.c

@@ -0,0 +1,16 @@
+// SPDX-FileCopyrightText: 1990-1994, Julianne Frances Haugh
+// SPDX-FileCopyrightText: 1996-1998, Marek Michałkiewicz
+// SPDX-FileCopyrightText: 2003-2006, Tomasz Kłoczko
+// SPDX-FileCopyrightText: 2008     , Nicolas François
+// SPDX-FileCopyrightText: 2023-2024, Alejandro Colomar <alx@kernel.org>
+// SPDX-License-Identifier: BSD-3-Clause
+
+
+#include <config.h>
+
+#include "alloc/reallocf.h"
+
+#include <stddef.h>
+
+
+extern inline void *reallocarrayf(void *p, size_t nmemb, size_t size);