StdLib: Add support for AArch64

- Use some files from ARM version.
- Use NetBSD software floating point library to provide floating point
  operations not handled directly by hardware floating point enabled
  GCC compiler.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Harry Liebel <Harry.Liebel@arm.com>
Reviewed-by: Olivier Martin <Olivier.Martin@arm.com>
Reviewed-by: Daryl McDaniel <edk2-lists@mc2research.org>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18118 6f19259b-4bc3-4df7-8a09-765794883524

StdLib/Include/Aarch64/machine/bswap.h

@@ -0,0 +1,13 @@
+/*      $NetBSD: bswap.h,v 1.4 2006/01/31 07:49:18 dsl Exp $      */
+
+/* Written by Manuel Bouyer. Public domain */
+
+#ifndef _MACHINE_BSWAP_H_
+#define _MACHINE_BSWAP_H_
+
+#include <machine/byte_swap.h>
+
+#define __BSWAP_RENAME
+#include <sys/bswap.h>
+
+#endif /* !_MACHINE_BSWAP_H_ */