Revert of [Parser] Introduce AstStringConstants to share constants across AstValueFactory

Revert of [Parser] Introduce AstStringConstants to share constants across AstValueFactory (patchset #4 id:80001 of https://codereview.chromium.org/2630343002/ )

Reason for revert:
Seems to break modules-namespace2 on gcstress.

Original issue's description:
> [Parser] Introduce AstStringConstants to share constants across AstValueFactory
> 
> Creates an AstStringConstants container which pre-initializes the
> string constants used by AstValueFactory. This ensures that all
> AstValueFactories will produce the same AstValue objects for constants,
> and so they can be used by the BytecodeGenerator without having to pass
> the AstValueFactory to it, enabling construction off-thread.
> 
> BUG=v8:5203
> 
> Review-Url: https://codereview.chromium.org/2630343002
> Cr-Commit-Position: refs/heads/master@{#42381}
> Committed: https://chromium.googlesource.com/v8/v8/+/d611496b8ed30af787d8668f96b400617c858508

TBR=ahaas@chromium.org,marja@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5203
Review-Url: https://codereview.chromium.org/2638783002
Cr-Commit-Position: refs/heads/master@{#42382}
Committed: https://chromium.googlesource.com/v8/v8/+/c8ac1a0ca52441b7e4aa3f7be0dda0d95b94a81c

[rmcilroy, 2017-01-16 16:35:04]

The CQ bit was checked by rmcilroy@chromium.org

[rmcilroy, 2017-01-16 16:35:04]

Created Revert of [Parser] Introduce AstStringConstants to share constants
across AstValueFactory

[commit-bot: I haz the power, 2017-01-16 16:35:08]

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, 2017-01-16 16:35:16]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1484584504101760, "parent_rev":
"d611496b8ed30af787d8668f96b400617c858508", "commit_rev":
"c8ac1a0ca52441b7e4aa3f7be0dda0d95b94a81c"}

[commit-bot: I haz the power, 2017-01-16 16:35:20]

Description was changed from

==========
Revert of [Parser] Introduce AstStringConstants to share constants across
AstValueFactory (patchset #4 id:80001 of
https://codereview.chromium.org/2630343002/ )

Reason for revert:
Seems to break modules-namespace2 on gcstress.

Original issue's description:
> [Parser] Introduce AstStringConstants to share constants across
AstValueFactory
> 
> Creates an AstStringConstants container which pre-initializes the
> string constants used by AstValueFactory. This ensures that all
> AstValueFactories will produce the same AstValue objects for constants,
> and so they can be used by the BytecodeGenerator without having to pass
> the AstValueFactory to it, enabling construction off-thread.
> 
> BUG=v8:5203
> 
> Review-Url: https://codereview.chromium.org/2630343002
> Cr-Commit-Position: refs/heads/master@{#42381}
> Committed:
https://chromium.googlesource.com/v8/v8/+/d611496b8ed30af787d8668f96b400617c8...

TBR=ahaas@chromium.org,marja@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5203
==========

to

==========
Revert of [Parser] Introduce AstStringConstants to share constants across
AstValueFactory (patchset #4 id:80001 of
https://codereview.chromium.org/2630343002/ )

Reason for revert:
Seems to break modules-namespace2 on gcstress.

Original issue's description:
> [Parser] Introduce AstStringConstants to share constants across
AstValueFactory
> 
> Creates an AstStringConstants container which pre-initializes the
> string constants used by AstValueFactory. This ensures that all
> AstValueFactories will produce the same AstValue objects for constants,
> and so they can be used by the BytecodeGenerator without having to pass
> the AstValueFactory to it, enabling construction off-thread.
> 
> BUG=v8:5203
> 
> Review-Url: https://codereview.chromium.org/2630343002
> Cr-Commit-Position: refs/heads/master@{#42381}
> Committed:
https://chromium.googlesource.com/v8/v8/+/d611496b8ed30af787d8668f96b400617c8...

TBR=ahaas@chromium.org,marja@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5203

Review-Url: https://codereview.chromium.org/2638783002
Cr-Commit-Position: refs/heads/master@{#42382}
Committed:
https://chromium.googlesource.com/v8/v8/+/c8ac1a0ca52441b7e4aa3f7be0dda0d95b9...
==========

[commit-bot: I haz the power, 2017-01-16 16:35:21]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/c8ac1a0ca52441b7e4aa3f7be0dda0d95b9...