Remove unused isc_astack unit

The isc_astack unit is now unused, so just remove it.

lib/isc/include/isc/astack.h

@@ -1,49 +0,0 @@
-/*
- * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
- *
- * SPDX-License-Identifier: MPL-2.0
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, you can obtain one at https://mozilla.org/MPL/2.0/.
- *
- * See the COPYRIGHT file distributed with this work for additional
- * information regarding copyright ownership.
- */
-
-#pragma once
-
-#include <inttypes.h>
-
-#include <isc/mem.h>
-#include <isc/types.h>
-
-isc_astack_t *
-isc_astack_new(isc_mem_t *mctx, size_t size);
-/*%<
- * Allocate and initialize a new array stack of size 'size'.
- */
-
-void
-isc_astack_destroy(isc_astack_t *stack);
-/*%<
- * Free an array stack 'stack'.
- *
- * Requires:
- * \li	'stack' is empty.
- */
-
-bool
-isc_astack_trypush(isc_astack_t *stack, void *obj);
-/*%<
- * Try to push 'obj' onto array stack 'astack'. On failure, either
- * because the stack size limit has been reached or because another
- * thread has already changed the stack pointer, return 'false'.
- */
-
-void *
-isc_astack_pop(isc_astack_t *stack);
-/*%<
- * Pop an object off of array stack 'stack'. If the stack is empty,
- * return NULL.
- */

lib/isc/include/isc/types.h

@@ -33,9 +33,8 @@
 
 /* Core Types.  Alphabetized by defined type. */
 
-typedef struct isc_astack isc_astack_t;		 /*%< Array-based fast stack */
-typedef struct isc_buffer isc_buffer_t;		 /*%< Buffer */
-typedef ISC_LIST(isc_buffer_t) isc_bufferlist_t; /*%< Buffer List */
+typedef struct isc_buffer isc_buffer_t;			  /*%< Buffer */
+typedef ISC_LIST(isc_buffer_t) isc_bufferlist_t;	  /*%< Buffer List */
 typedef struct isc_constregion	   isc_constregion_t;	  /*%< Const region */
 typedef struct isc_consttextregion isc_consttextregion_t; /*%< Const Text Region
 							   */