Whenever we insert new code in the module, we call {set_code} and
{PatchJumpTable}. This CL refactors these two calls into a new
{InstallCode} method. This method will be extended in a future CL to
maintain a counter of potentially dead code and trigger GC.

R=mstarzinger@chromium.org

Bug: v8:8217
Change-Id: I1a1421806c8518cf7b6b78fe4aa2e969d4e4dde6
Reviewed-on: https://chromium-review.googlesource.com/1243003
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56214}