Currently the CompileLazy builtin checks the SFI expliciltly for FCG code. This means
if the SFI has bytecode we have to go through to the runtime to install the
interpreter entry trampoline into the JSFunction object.

Modify the builtin to always put the SFI code object into the JSFunction unless it's
the lazy compile stub on the SFI as well.

BUG=v8:4380

Review-Url: https://codereview.chromium.org/2583693003
Cr-Commit-Position: refs/heads/master@{#42034}