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, 90 insertions, 0 deletions

diff --git a/sysdeps/aarch64/crti.S b/sysdeps/aarch64/crti.S
new file mode 100644
index 0000000000..2db7b6793f
--- /dev/null
+++ b/sysdeps/aarch64/crti.S
@@ -0,0 +1,90 @@
+/* Special .init and .fini section support for AArch64.
+   Copyright (C) 1995-2014 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.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file with other
+   programs, and to distribute those programs without any restriction
+   coming from the use of this file. (The GNU Lesser General Public
+   License restrictions do apply in other respects; for example, they
+   cover modification of the file, and distribution when not linked
+   into another program.)
+
+   Note that people who make modified versions of this file are not
+   obligated to grant this special exception for their modified
+   versions; it is their choice whether to do so. The GNU Lesser
+   General Public License gives permission to release a modified
+   version without this exception; this exception also makes it
+   possible to release a modified version which carries forward this
+   exception.
+
+   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/>.  */
+
+/* crti.S puts a function prologue at the beginning of the .init and
+   .fini sections and defines global symbols for those addresses, so
+   they can be called as functions.  The symbols _init and _fini are
+   magic and cause the linker to emit DT_INIT and DT_FINI.  */
+
+#include <libc-symbols.h>
+
+#ifndef PREINIT_FUNCTION
+# define PREINIT_FUNCTION __gmon_start__
+#endif
+
+#ifndef PREINIT_FUNCTION_WEAK
+# define PREINIT_FUNCTION_WEAK 1
+#endif
+
+#if PREINIT_FUNCTION_WEAK
+	weak_extern (PREINIT_FUNCTION)
+#else
+	.hidden PREINIT_FUNCTION
+#endif
+
+#if PREINIT_FUNCTION_WEAK
+	.align	2
+	.type	call_weak_fn, %function
+call_weak_fn:
+	adrp	x0, :got:PREINIT_FUNCTION
+	ldr	x0, [x0, #:got_lo12:PREINIT_FUNCTION]
+	cbz	x0, 1f
+	b	PREINIT_FUNCTION
+1:
+	RET
+	.size	call_weak_fn, .-call_weak_fn
+#endif
+
+	.section .init,"ax",%progbits
+	.align	2
+	.global	_init
+	.type	_init, %function
+_init:
+	stp	x29, x30, [sp, -16]!
+	mov	x29, sp
+#if PREINIT_FUNCTION_WEAK
+	bl	call_weak_fn
+#else
+	bl	PREINIT_FUNCTION
+#endif
+
+	.section	.fini,"ax",%progbits
+	.align	2
+	.global	_fini
+	.type	_fini, %function
+_fini:
+	stp	x29, x30, [sp, -16]!
+	mov	x29, sp