Port 51ded9d3

Original Commit Message:

    This is a reland of d8f564ea

    Original change's description:
    > Reland: Remove SFI code field
    >
    > Remove the SharedFunctionInfo code field, inferring the code object
    > from the function_data field instead. In some cases, the function_data
    > field can now hold a Code object (e.g. some WASM cases).
    >
    > (Reland of https://chromium-review.googlesource.com/952452)
    >
    > TBR=mstarzinger@chromium.org
    >
    > Bug: chromium:783853
    > Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
    > Change-Id: I10ea5be7ceed1b51362a2fad9be7397624d69343
    > Reviewed-on: https://chromium-review.googlesource.com/970649
    > Commit-Queue: Leszek Swirski <leszeks@chromium.org>
    > Reviewed-by: Yang Guo <yangguo@chromium.org>
    > Reviewed-by: Jakob Gruber <jgruber@chromium.org>
    > Reviewed-by: Leszek Swirski <leszeks@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#52136}

R=leszeks@chromium.org, joransiu@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: I86c5a46a866830a2150ff9366be12a09f111240f
Reviewed-on: https://chromium-review.googlesource.com/976624Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#52165}