Port 72c37076

Original Commit Message:

    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.

R=rmcilroy@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=v8:4380
LOG=N

Review-Url: https://codereview.chromium.org/2602383003
Cr-Commit-Position: refs/heads/master@{#42046}