The former will handle loads of predeclared global variables (vars and
functions), lets, consts and undeclared variables. The latter will handle
named loads from explicit receiver. In addition, named loads does not
depend of the TypeofMode.

TypeofMode related cleanup will be done in the follow-up CL.

BUG=chromium:576312
LOG=Y
TBR=bmeurer@chromium.org

Review-Url: https://codereview.chromium.org/1912633002
Cr-Commit-Position: refs/heads/master@{#36965}