Instead of updating the SharedFuntionInfo set the name property on
the function directly.

BUG=v8:4278
LOG=N
R=verwaest@chromium.org, littledan@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1227523003

Cr-Commit-Position: refs/heads/master@{#29558}