Port 1e277012

Original commit message:
    Avoid write barriers when storing values in the root set, and use
    cheaper write barriers for storing maps or tagged pointers. Also
    improve the generated code for write barriers, utilizing the out
    of line code mechanism that is available to TurboFan backends,
    which moves the unlikely case out of the hot path.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, dstence@us.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1431923003

Cr-Commit-Position: refs/heads/master@{#31927}