Fix int64 lowering on big-endian architectures.

test/mjsunit/mjsunit.status

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
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@@ skipping 405 matching lines @@
 }],  # 'no_i18n == True and mode == debug'
 
 ##############################################################################
 ['byteorder == big', {
   # Emscripten requires little-endian, skip all tests on big endian platforms.
   'asm/embenchen/*': [SKIP],
   'asm/poppler/*': [SKIP],
   'asm/sqlite3/*': [SKIP],
   # TODO(mips-team): Fix Wasm for big-endian.
   'wasm/*': [SKIP],
-  'regress/regress-599717': [SKIP],
-  'regress/regress-599719': [SKIP],
 }],  # 'byteorder == big'
 
 ##############################################################################
 ['arch == arm64 or arch == android_arm64', {
 
   # arm64 TF timeout.
   'regress/regress-1257': [PASS, TIMEOUT],
 
   # Requires bigger stack size in the Genesis and if stack size is increased,
   # the test requires too much time to run.  However, the problem test covers
@@ skipping 439 matching lines @@
 ##############################################################################
 ['gcov_coverage', {
   # Tests taking too long.
   'array-functions-prototype-misc': [SKIP],
 
   # Stack overflow.
   'big-array-literal': [SKIP],
 }],  # 'gcov_coverage'
 
 ]