Failure is due to different endianness on big endian. The test now passes on
both big-endian and little-endian architectures.

TEST=cctest/test-code-stubs-mips64/ConvertDToI
BUG=

Review-Url: https://codereview.chromium.org/2157373002
Cr-Commit-Position: refs/heads/master@{#38022}