Add stub functions to build libkvm. There will be added, but we need them

now get the toolchain target building.

Differential Revision:	https://reviews.freebsd.org/D2185
Sponsored by:	The FreeBSD Foundation

lib/libkvm/kvm_aarch64.c

@@ -0,0 +1,64 @@
+/*-
+ * Copyright (c) 2014 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Andrew Turner under
+ * sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+
+#include <limits.h>
+#include <kvm.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "kvm_private.h"
+
+void
+_kvm_freevtop(kvm_t *kd)
+{
+
+	printf("_kvm_freevtop\n");
+	abort();
+}
+
+int
+_kvm_initvtop(kvm_t *kd)
+{
+
+	printf("_kvm_initvtop\n");
+	abort();
+}
+
+int
+_kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
+{
+
+	printf("_kvm_kvatop\n");
+	abort();
+}