[turbofan] Extend the type fixup to LoadField as well.

[turbofan] Extend the type fixup to LoadField as well.

For LoadElimination we must not replace LoadField nodes with other nodes
whose types are not a subtype of the original LoadField type, as that
breaks the verifier. We already fixed that earlier for store to load
forwarding, but the fix didn't cover LoadField forwarding.

This actually still generates the correct code even w/o the fix, but
since recently fails due to stronger checking in representation
selection. So this makes clusterfuzz happy again.

R=mvstanton@chromium.org
BUG=chromium:607899
LOG=n

Committed: https://crrev.com/c0e65ea85d09780a13685ff06a83b38cef0b279a
Cr-Commit-Position: refs/heads/master@{#35930}

[mvstanton, 2016-05-02 11:01:57]

lgtm

[mvstanton, 2016-05-02 11:02:06]

The CQ bit was checked by mvstanton@chromium.org

[commit-bot: I haz the power, 2016-05-02 11:02:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1934973002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1934973002/1

[commit-bot: I haz the power, 2016-05-02 11:28:50]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-02 11:30:23]

Description was changed from

==========
[turbofan] Extend the type fixup to LoadField as well.

For LoadElimination we must not replace LoadField nodes with other nodes
whose types are not a subtype of the original LoadField type, as that
breaks the verifier. We already fixed that earlier for store to load
forwarding, but the fix didn't cover LoadField forwarding.

This actually still generates the correct code even w/o the fix, but
since recently fails due to stronger checking in representation
selection. So this makes clusterfuzz happy again.

R=mvstanton@chromium.org
BUG=chromium:607899
LOG=n
==========

to

==========
[turbofan] Extend the type fixup to LoadField as well.

For LoadElimination we must not replace LoadField nodes with other nodes
whose types are not a subtype of the original LoadField type, as that
breaks the verifier. We already fixed that earlier for store to load
forwarding, but the fix didn't cover LoadField forwarding.

This actually still generates the correct code even w/o the fix, but
since recently fails due to stronger checking in representation
selection. So this makes clusterfuzz happy again.

R=mvstanton@chromium.org
BUG=chromium:607899
LOG=n

Committed: https://crrev.com/c0e65ea85d09780a13685ff06a83b38cef0b279a
Cr-Commit-Position: refs/heads/master@{#35930}
==========

[commit-bot: I haz the power, 2016-05-02 11:30:24]

Patchset 1 (id:??) landed as
https://crrev.com/c0e65ea85d09780a13685ff06a83b38cef0b279a
Cr-Commit-Position: refs/heads/master@{#35930}