$ svn log -r 317070:317078 http://llvm.org/svn/llvm-project/

Aha, it has to be this one:

------------------------------------------------------------------------
r317076 | rsmith | 2017-10-31 21:52:12 -0700 (Tue, 31 Oct 2017) | 2 lines

Fix -Wunused-private-field to fire regardless of which implicit special members have been implicitly declared.

------------------------------------------------------------------------

V8 fix: https://chromium-review.googlesource.com/c/v8/v8/+/749117

Currently building to see if there are more...

With these additional patches, I get through a full debug build on Linux:

https://chromium-review.googlesource.com/c/chromium/src/+/749685
https://chromium-review.googlesource.com/c/chromium/src/+/749736

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/c9168fc5deaead5235468e55d117df0fa2fb69b4

commit c9168fc5deaead5235468e55d117df0fa2fb69b4
Author: Hans Wennborg <hans@chromium.org>
Date: Wed Nov 01 20:46:22 2017

Remove unused member variable TranslatedFrame::isolate_

Recent Clang versions (r317076+) warn about this.

Bug:  chromium:780523 
Change-Id: Iccc8d675ce4700f67dedfaa60bc6662b03b55ceb
Reviewed-on: https://chromium-review.googlesource.com/749117
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49066}
[modify] https://crrev.com/c9168fc5deaead5235468e55d117df0fa2fb69b4/src/deoptimizer.cc
[modify] https://crrev.com/c9168fc5deaead5235468e55d117df0fa2fb69b4/src/deoptimizer.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7c49d0029ea3332486b9ca851cda91e80a3ff10c

commit 7c49d0029ea3332486b9ca851cda91e80a3ff10c
Author: Hans Wennborg <hans@chromium.org>
Date: Wed Nov 01 21:40:02 2017

Remove unused member variable from ppb_var_unittest.cc

Recent Clang versions (r317076+) warn about this.

TBR=dmichael

Bug:  780523 
Change-Id: Id3c239f109119aec9167096bed87a9b886632739
Reviewed-on: https://chromium-review.googlesource.com/749736
Reviewed-by: Hans Wennborg <hans@chromium.org>
Commit-Queue: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513282}
[modify] https://crrev.com/7c49d0029ea3332486b9ca851cda91e80a3ff10c/ppapi/proxy/ppb_var_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b8183fe5f9d362e750912d222840ad96cbe1c969

commit b8183fe5f9d362e750912d222840ad96cbe1c969
Author: Hans Wennborg <hans@chromium.org>
Date: Wed Nov 01 22:31:06 2017

SmartClip: Remove unused member variable

Recent Clang versions (r317076+) warn about this.

Bug:  780523 
Change-Id: I6e608b49ef3bd8579165cf831f6b44c67bea3f2a
Reviewed-on: https://chromium-review.googlesource.com/749685
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513302}
[modify] https://crrev.com/b8183fe5f9d362e750912d222840ad96cbe1c969/third_party/WebKit/Source/core/frame/SmartClip.cpp
[modify] https://crrev.com/b8183fe5f9d362e750912d222840ad96cbe1c969/third_party/WebKit/Source/core/frame/SmartClip.h

Just waiting for the next V8 roll now. This one has my change:
https://chromium-review.googlesource.com/c/chromium/src/+/750121

The V8 roll landed, so bots should start cycling green now.

Requesting merge of c9168fc5deaead5235468e55d117df0fa2fb69b4 (comment #4) to V8 6.3 to fix compilation of the Beta branch with recent Clang. Node.js will likely also appreciate this.

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

If all merges have been completed, please remove any remaining Merge-Approved labels from this issue.

Thanks for your time! To disable nags, add the Disable-Nags label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/31c91fdbccb117ea492c536e345124519534006f

commit 31c91fdbccb117ea492c536e345124519534006f
Author: Jakob Kummerow <jkummerow@chromium.org>
Date: Tue Nov 14 00:50:20 2017

Merged: Remove unused member variable TranslatedFrame::isolate_

Revision: c9168fc5deaead5235468e55d117df0fa2fb69b4

BUG= chromium:780523 
LOG=N
NOTRY=true
NOPRESUBMIT=true
NOTREECHECKS=true
R=adamk@chromium.org

Change-Id: I25e200313def8ed09f0230f643969cded348df28
Reviewed-on: https://chromium-review.googlesource.com/767489
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/branch-heads/6.3@{#65}
Cr-Branched-From: 094a7c93dcdcd921de3883ba4674b7e1a0feffbe-refs/heads/6.3.292@{#1}
Cr-Branched-From: 18b8fbb528a8021e04a029e06eafee50b918bce0-refs/heads/master@{#48432}
[modify] https://crrev.com/31c91fdbccb117ea492c536e345124519534006f/src/deoptimizer.cc
[modify] https://crrev.com/31c91fdbccb117ea492c536e345124519534006f/src/deoptimizer.h