Print finalize incremental marking event in idle notification.

BUG=

Review URL: https://codereview.chromium.org/775013002

Cr-Commit-Position: refs/heads/master@{#25631}
[turbofan] Initial work on cleaning up the Node class.

- Remove use_count_, only used for debug builds and tests.
- Use BitField instead of the unreliable C++ bit fields.
- Improve memory layout.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/780503002

Cr-Commit-Position: refs/heads/master@{#25632}
[turbofan] Reuse forward fixpoint algorithm in Typer by making it a Reducer.

R=jarin@chromium.org
BUG=

Review URL: https://codereview.chromium.org/769303002

Cr-Commit-Position: refs/heads/master@{#25633}
CheckPrototypes uses weak cells to embed maps.

BUG=v8:3629
LOG=N

Review URL: https://codereview.chromium.org/770373002

Cr-Commit-Position: refs/heads/master@{#25634}
MIPS: Fix ambiguous double constant loading after adding checked load/store operators.

The V8_INFINITY macro expands to constant expression of type float.

TEST=mjsunit/constant-folding-2
BUG=
R=balazs.kilvady@imgtec.com

Review URL: https://codereview.chromium.org/779433003

Cr-Commit-Position: refs/heads/master@{#25635}
MIPS: Improve pushing arguments on stack.

TEST=
BUG=
R=paul.lind@imgtec.com

Review URL: https://codereview.chromium.org/769283002

Cr-Commit-Position: refs/heads/master@{#25636}