[turbofan] Desugar lookup slot optimization in graph builder.

[turbofan] Desugar lookup slot optimization in graph builder.

This moves the optimization for variables loads targeting lookup slots
in DYNAMIC_GLOBAL and DYNAMIC_LOCAL mode into the AstGraphBuilder. This
way we implicitly get all optimizations that target global loads and
context loads for free.

R=bmeurer@chromium.org
BUG=v8:4513
LOG=n

Committed: https://crrev.com/3e73ce49545b04125f75f4dd720d5844933920b0
Cr-Commit-Position: refs/heads/master@{#31713}

[Benedikt Meurer, 2015-11-02 13:15:56]

LGTM with nits.

https://codereview.chromium.org/1424943008/diff/1/src/compiler/ast-graph-buil...
File src/compiler/ast-graph-builder.cc (right):

https://codereview.chromium.org/1424943008/diff/1/src/compiler/ast-graph-buil...
src/compiler/ast-graph-builder.cc:3068: static const int kMaxCheckDepth = 30;
Nit: static is unnecessary here. Anonymous namespace implies static linkage.

https://codereview.chromium.org/1424943008/diff/1/src/compiler/ast-graph-buil...
src/compiler/ast-graph-builder.cc:3071: static const uint32_t kFullCheckRequired
= -1;
Nit: static is unnecessary here. Anonymous namespace implies static linkage.

[Michael Starzinger, 2015-11-02 13:35:39]

https://codereview.chromium.org/1424943008/diff/1/src/compiler/ast-graph-buil...
File src/compiler/ast-graph-builder.cc (right):

https://codereview.chromium.org/1424943008/diff/1/src/compiler/ast-graph-buil...
src/compiler/ast-graph-builder.cc:3068: static const int kMaxCheckDepth = 30;
On 2015/11/02 13:15:55, Benedikt Meurer wrote:
> Nit: static is unnecessary here. Anonymous namespace implies static linkage.

Done.

https://codereview.chromium.org/1424943008/diff/1/src/compiler/ast-graph-buil...
src/compiler/ast-graph-builder.cc:3071: static const uint32_t kFullCheckRequired
= -1;
On 2015/11/02 13:15:55, Benedikt Meurer wrote:
> Nit: static is unnecessary here. Anonymous namespace implies static linkage.

Done.

[Michael Starzinger, 2015-11-02 13:53:40]

The CQ bit was checked by mstarzinger@chromium.org

[Michael Starzinger, 2015-11-02 13:53:40]

The patchset sent to the CQ was uploaded after l-g-t-m from bmeurer@chromium.org
Link to the patchset: https://codereview.chromium.org/1424943008/#ps20001
(title: "Addressed comment.")

[commit-bot: I haz the power, 2015-11-02 13:53:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1424943008/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1424943008/20001

[commit-bot: I haz the power, 2015-11-02 13:55:28]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-11-02 13:55:41]

Patchset 2 (id:??) landed as
https://crrev.com/3e73ce49545b04125f75f4dd720d5844933920b0
Cr-Commit-Position: refs/heads/master@{#31713}