Revert of Pass -no-canonical-prefixes to clang by default.

Revert of Pass -no-canonical-prefixes to clang by default. (patchset #3 id:40001 of https://codereview.chromium.org/2842063002/ )

Reason for revert:
This is possibly breaking CrOS builds, see comment #30 and the updates on crbug.com/712797.

Original issue's description:
> Pass -no-canonical-prefixes to clang by default.
> 
> When clang invokes its subtools, by default it passes a default
> path to them as an absolute path. We don't really need this to
> be absolute, and having goma stores the the command lines that
> in its cache entry keys, which means that differing absolute
> paths can cause cache misses. So, this CL tells clang to
> stop doing that.
> 
> R=thakis@chromium.org, shinyak@chromium.org
> BUG=706224
> 
> Review-Url: https://codereview.chromium.org/2842063002
> Cr-Commit-Position: refs/heads/master@{#478859}
> Committed: https://chromium.googlesource.com/chromium/src/+/0e8121522085f344b83cc86c514e4bfb7f7c5a22

TBR=shinyak@chromium.org,thakis@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=706224
Review-Url: https://codereview.chromium.org/2936053003
Cr-Commit-Position: refs/heads/master@{#479193}
Committed: https://chromium.googlesource.com/chromium/src/+/cc66e92a5fcbb8810000303fc1d93094561479a5

[Dirk Pranke, 2017-06-13 23:03:08]

The CQ bit was checked by dpranke@chromium.org

[Dirk Pranke, 2017-06-13 23:03:08]

Created Revert of Pass -no-canonical-prefixes to clang by default.

[commit-bot: I haz the power, 2017-06-13 23:03:45]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-06-13 23:04:08]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1497394988105860, "parent_rev":
"2a528c127971a743147814e088c63826ad22ef16", "commit_rev":
"cc66e92a5fcbb8810000303fc1d93094561479a5"}

[commit-bot: I haz the power, 2017-06-13 23:04:21]

Description was changed from

==========
Revert of Pass -no-canonical-prefixes to clang by default. (patchset #3 id:40001
of https://codereview.chromium.org/2842063002/ )

Reason for revert:
This is possibly breaking CrOS builds, see comment #30 and the updates on
crbug.com/712797.

Original issue's description:
> Pass -no-canonical-prefixes to clang by default.
> 
> When clang invokes its subtools, by default it passes a default
> path to them as an absolute path. We don't really need this to
> be absolute, and having goma stores the the command lines that
> in its cache entry keys, which means that differing absolute
> paths can cause cache misses. So, this CL tells clang to
> stop doing that.
> 
> R=thakis@chromium.org, shinyak@chromium.org
> BUG=706224
> 
> Review-Url: https://codereview.chromium.org/2842063002
> Cr-Commit-Position: refs/heads/master@{#478859}
> Committed:
https://chromium.googlesource.com/chromium/src/+/0e8121522085f344b83cc86c514e...

TBR=shinyak@chromium.org,thakis@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=706224
==========

to

==========
Revert of Pass -no-canonical-prefixes to clang by default. (patchset #3 id:40001
of https://codereview.chromium.org/2842063002/ )

Reason for revert:
This is possibly breaking CrOS builds, see comment #30 and the updates on
crbug.com/712797.

Original issue's description:
> Pass -no-canonical-prefixes to clang by default.
> 
> When clang invokes its subtools, by default it passes a default
> path to them as an absolute path. We don't really need this to
> be absolute, and having goma stores the the command lines that
> in its cache entry keys, which means that differing absolute
> paths can cause cache misses. So, this CL tells clang to
> stop doing that.
> 
> R=thakis@chromium.org, shinyak@chromium.org
> BUG=706224
> 
> Review-Url: https://codereview.chromium.org/2842063002
> Cr-Commit-Position: refs/heads/master@{#478859}
> Committed:
https://chromium.googlesource.com/chromium/src/+/0e8121522085f344b83cc86c514e...

TBR=shinyak@chromium.org,thakis@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=706224

Review-Url: https://codereview.chromium.org/2936053003
Cr-Commit-Position: refs/heads/master@{#479193}
Committed:
https://chromium.googlesource.com/chromium/src/+/cc66e92a5fcbb8810000303fc1d9...
==========

[commit-bot: I haz the power, 2017-06-13 23:04:23]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/cc66e92a5fcbb8810000303fc1d9...

[Dirk Pranke, 2017-07-11 01:02:40]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/2974863002/ by dpranke@chromium.org.

The reason for reverting is: Trying again now that the compiler has been fixed..