Reland "[turbofan] Fix control reducer bug with NTLs."

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/789083004

Cr-Commit-Position: refs/heads/master@{#25740}
Reland "Use same blob format for internal and external snapshots."

Review URL: https://codereview.chromium.org/791723004

Cr-Commit-Position: refs/heads/master@{#25741}
[turbofan] update register allocator with auto, nullptr and ZoneVector

BUG=

Review URL: https://codereview.chromium.org/789083005

Cr-Commit-Position: refs/heads/master@{#25742}