This adds the v8-side fuzzer executables for smoke testing.
This also renames the old gyp targets to stay consistent
with chromium.

Naming convention for type X after the rename:
library: X_fuzzer (gn), X_fuzzer_lib (gyp)
executable v8: v8_simple_X_fuzzer
executable chromium: v8_X_fuzzer

BUG=chromium:474921

Review-Url: https://codereview.chromium.org/2032363002
Cr-Commit-Position: refs/heads/master@{#36713}