When a FunctionEntryHook parameter was passed to isolate creation,
we ignored any existing snapshots anyway. Since the ability to
bootstrap from scratch will be removed from snapshot builds, the
FunctionEntryHook feature must depend on a no-snapshot build.

BUG=v8:6055

Review-Url: https://codereview.chromium.org/2733203002
Cr-Commit-Position: refs/heads/master@{#43779}