Port 16c8485a

Original commit message:
Replaces StoreGlobalCell / LoadGlobalCell with NamedField variants that use write barriers.

R=mbrandy@us.ibm.com, svenpanne@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1018333003

Cr-Commit-Position: refs/heads/master@{#27380}