Sync sha512-armv8.pl up to 753316232243ccbf86b96c1c51ffcb41651d9ad5.

This imports 753316232243ccbf86b96c1c51ffcb41651d9ad5,
46f4e1bec51dc96fa275c168752aa34359d9ee51, and
32bbb62ea634239e7cb91d6450ba23517082bab6.

The last commit fixes a detection of big-endian aarch64 in the kernel,
which we do not support at all, but is imported to reduce the upstream
diff. Though it points out a messy part of arm_arch.h: __ARMEL__ and
__ARMEB__ are specific to 32-bit ARM. __AARCH64EB__ and __AARCH64EL__
are the 64-bit ones. But OpenSSL's arm_arch.h defines __ARME[LB]__ for
aarch64 and uses it in perlasm. We should fix the files upstream to
look at the aarch64 ones. (Indeed our own base.h assumes __ARMEL__
implies 32-bit ARM.)

Change-Id: I6c2241e103a97e8c3599cdfa43dcc6f30d4a2581
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/50806
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

crypto/fipsmodule/sha/asm/sha512-armv8.pl

diff --git a/crypto/fipsmodule/sha/asm/sha512-armv8.pl b/crypto/fipsmodule/sha/asm/sha512-armv8.pl
index 01154c2..e961312 100644
--- a/crypto/fipsmodule/sha/asm/sha512-armv8.pl
+++ b/crypto/fipsmodule/sha/asm/sha512-armv8.pl
@@ -1,5 +1,5 @@
 #! /usr/bin/env perl
-# Copyright 2014-2016 The OpenSSL Project Authors. All Rights Reserved.
+# Copyright 2014-2020 The OpenSSL Project Authors. All Rights Reserved.
 #
 # Licensed under the OpenSSL license (the "License").  You may not use
 # this file except in compliance with the License.  You can obtain a copy
@@ -27,6 +27,7 @@
 # Denver	2.01		10.5 (+26%)	6.70 (+8%)
 # X-Gene			20.0 (+100%)	12.8 (+300%(***))
 # Mongoose	2.36		13.0 (+50%)	8.36 (+33%)
+# Kryo		1.92		17.4 (+30%)	11.2 (+8%)
 #
 # (*)	Software SHA256 results are of lesser relevance, presented
 #	mostly for informational purposes.
@@ -35,7 +36,7 @@
 #	on Cortex-A53 (or by 4 cycles per round).
 # (***)	Super-impressive coefficients over gcc-generated code are
 #	indication of some compiler "pathology", most notably code
-#	generated with -mgeneral-regs-only is significanty faster
+#	generated with -mgeneral-regs-only is significantly faster
 #	and the gap is only 40-90%.
 
 $output=pop;
@@ -89,7 +90,7 @@
    $T0=@X[$i+3] if ($i<11);
 
 $code.=<<___	if ($i<16);
-#ifndef	__ARMEB__
+#ifndef	__AARCH64EB__
 	rev	@X[$i],@X[$i]			// $i
 #endif
 ___