This isolates all files necessary to run jsfunfuzz. The fuzz
harness is copied into the jsfunfuzz directory and will be
deleted in the old location after the migration to swarming.
BUG=chromium:535160
LOG=n
NOTRY=true
Review URL: https://codereview.chromium.org/1706223002
Cr-Commit-Position: refs/heads/master@{#34122}
