This adds a new pass MemoryOptimizer that walks over the effect chain
from Start and lowers all Allocate, LoadField, StoreField, LoadElement,
and StoreElement nodes, trying to fold allocations into allocation
groups and eliminate write barriers on StoreField and StoreElement if
possible (i.e. if the object belongs to the current allocation group and
that group allocates in new space).

R=hpayer@chromium.org, jarin@chromium.org
BUG=v8:4931, chromium:580959
LOG=n

Review-Url: https://codereview.chromium.org/1963583004
Cr-Commit-Position: refs/heads/master@{#36128}

This changes closure creation to lower to inline allocations when
possible instead of going through the FastNewClosureStub. It allows us
to leverage all advantages of inline allocations on closures. Note that
it is only safe to embed the raw entry point of the compile lazy stub
into the code, because that stub is immortal and immovable.

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/1573153002

Cr-Commit-Position: refs/heads/master@{#35499}

This adds initial support for inline allocation of object and array
literals to the JSCreateLowering pass. It's basically identical to
what Crankshaft does.

This also unstages the TurboFan escape analysis, as the lowering seems
to trigger a bunch of bugs in it; those bugs will be fixed separately,
and we will re-enable escape analysis afterwards.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1698783002

Cr-Commit-Position: refs/heads/master@{#33972}

This moves the JSCreate related functionality from JSTypedLowering into
a dedicated JSCreateLowering reducer. This is in preparation of landing
the support for optimized literals in TurboFan, which would blow up
JSTypedLowering quite seriously otherwise.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/1678833002

Cr-Commit-Position: refs/heads/master@{#33813}