Relocate AArch64 from ports to libc.

This patch moves the AArch64 port to the main sysdeps hierarchy.  The
move is essentially:

  git mv ports/sysdeps/aarch64 sysdeps/aarch64
  git mv ports/sysdeps/unix/sysv/linux/aarch64 sysdeps/unix/sysv/linux/aarch64

The README is updated and I've updated ChangeLog.aarch64 along the
lines of the ARM move.  The AArch64 build has been tested to confirm
that there were no changes in objdump -dr output or the shared
objects.

1 files changed, 60 insertions, 0 deletions

diff --git a/sysdeps/aarch64/jmpbuf-offsets.h b/sysdeps/aarch64/jmpbuf-offsets.h
new file mode 100644
index 0000000000..bcf2afa555
--- /dev/null
+++ b/sysdeps/aarch64/jmpbuf-offsets.h
@@ -0,0 +1,60 @@
+/* Copyright (C) 2006-2014 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define JB_X19            0
+#define JB_X20            1
+#define JB_X21            2
+#define JB_X22            3
+#define JB_X23            4
+#define JB_X24            5
+#define JB_X25            6
+#define JB_X26            7
+#define JB_X27            8
+#define JB_X28            9
+#define JB_X29           10
+#define JB_LR            11
+#define JB_SP		 13
+
+#define JB_D8		 14
+#define JB_D9		 15
+#define JB_D10		 16
+#define JB_D11		 17
+#define JB_D12		 18
+#define JB_D13		 19
+#define JB_D14		 20
+#define JB_D15		 21
+
+#ifndef  __ASSEMBLER__
+#include <setjmp.h>
+#include <stdint.h>
+#include <sysdep.h>
+
+static inline uintptr_t __attribute__ ((unused))
+_jmpbuf_sp (__jmp_buf jmpbuf)
+{
+  uintptr_t sp = jmpbuf[JB_SP];
+#ifdef PTR_DEMANGLE
+  PTR_DEMANGLE (sp);
+#endif
+  return sp;
+}
+#endif
+
+/* Helper for generic ____longjmp_chk(). */
+#define JB_FRAME_ADDRESS(buf) \
+  ((void *) _jmpbuf_sp (buf))