QueryRegEnumerationInfo() and QueryRegSubkey().
Also added test suite.

BUG=769590
TEST=chrome_elf_unittests.exe, NtRegistryTest.*

Cq-Include-Trybots: master.tryserver.chromium.win:win10_chromium_x64_rel_ng
Change-Id: I6fb1c08c361c6d9fff001cbe67f9b43da4a988d8
Reviewed-on: https://chromium-review.googlesource.com/673830
Commit-Queue: Penny MacNeil <pennymac@chromium.org>
Reviewed-by: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#506086}