x86/asm: Annotate aliases

_key_expansion_128 is an alias to _key_expansion_256a, __memcpy to
memcpy, xen_syscall32_target to xen_sysenter_target, and so on. Annotate
them all using the new SYM_FUNC_START_ALIAS, SYM_FUNC_START_LOCAL_ALIAS,
and SYM_FUNC_END_ALIAS. This will make the tools generating the
debuginfo happy as it avoids nesting and double symbols.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Juergen Gross <jgross@suse.com> [xen parts]
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/20191011115108.12392-10-jslaby@suse.cz