Use variable tracking from ExpressionScopes rather than the PatternRewriter and
PreParserExpression::variables_ to declare variables.

We only figure out that variables are non-simple parameters once we see the
first non-simple parameter. This still uses the pattern rewriter to make
variables non-simple (kLet instead of kVar).

Change-Id: I4a4ee4852d667c26806bb24896722cfea3e093f2
Reviewed-on: https://chromium-review.googlesource.com/c/1417630Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58954}

Storing a VariableProxy in declarations means that a declaration and
initialisation assignment are tightly coupled to use the same var. In
particular, this means that Var declarations in with scopes have to
clone the VariableProxy to split the declaration and initializer LHS
lookup.

This patch changes declarations to point directly to the Variable, not
the VariableProxy. This will allow future refactoring to decouple
declarations and initialisations.

Change-Id: I0baa77bfd12fe175f9521d292740d7d712cffd37
Reviewed-on: https://chromium-review.googlesource.com/c/1406683Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58843}

This way, we can also check the return code of d8. We currently have a
bug (6981) which makes failing tests not being detected, even though
the failure message is (sometimes) being printed.
After this refactoring, we can write tests for our mjsunit test
functions.

R=machenbach@chromium.org

Bug: v8:6981
Change-Id: I0aa0abcb0f9a4f622a1e1d1a4d826da1e6eb4f07
Reviewed-on: https://chromium-review.googlesource.com/737991Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48951}

This avoids spending lots of time in Scope::RemoveUnresolved for very long
variable declaration lists.

BUG=v8:4699
LOG=n

Review URL: https://codereview.chromium.org/1655313003

Cr-Commit-Position: refs/heads/master@{#34047}

http://crrev.com/80a1e004f4ef619b54a2d87bf2108719a8411860 was reverted
due to a Blink test failure. That test has been marked as failing on
the Blink side in https://chromium.googlesource.com/chromium/src/+/ac11c6df133.

BUG=v8:811
LOG=y
TBR=rossberg@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1409093005

Cr-Commit-Position: refs/heads/master@{#31842}

Revert of Revert "Revert of [es6] Implement destructuring binding in try/catch" (patchset #2 id:20001 of https://codereview.chromium.org/1411323008/ )

Reason for revert:
[Sheriff] Breaks a layout test:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/2750

Please request rebase upstream first if intended.

Original issue's description:
> Revert "Revert of [es6] Implement destructuring binding in try/catch"
>
> Reland try/catch destructuring with a fix for the MemorySanitizer failure:
> initialization_pos needs to be initialized in the DeclarationDescriptor.
>
> This is a one line fix to http://crrev.com/a316db995e6e4253664920652ed4e5a38b2caeba
>
> BUG=v8:811
> LOG=y
>
> Committed: https://crrev.com/80a1e004f4ef619b54a2d87bf2108719a8411860
> Cr-Commit-Position: refs/heads/master@{#31834}

TBR=littledan@chromium.org,rossberg@chromium.org,adamk@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:811

Review URL: https://codereview.chromium.org/1421193006

Cr-Commit-Position: refs/heads/master@{#31840}

Reland try/catch destructuring with a fix for the MemorySanitizer failure:
initialization_pos needs to be initialized in the DeclarationDescriptor.

This is a one line fix to http://crrev.com/a316db995e6e4253664920652ed4e5a38b2caeba

BUG=v8:811
LOG=y

Review URL: https://codereview.chromium.org/1411323008

Cr-Commit-Position: refs/heads/master@{#31834}

Revert of [es6] Implement destructuring binding in try/catch (patchset #3 id:40001 of https://codereview.chromium.org/1417483014/ )

Reason for revert:
MSAN errors on arm64: http://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/builds/5123/

Original issue's description:
> [es6] Implement destructuring binding in try/catch
>
> The approach is to desugar
>
>   try { ... }
>   catch ({x, y}) { ... }
>
> into
>
>   try { ... }
>   catch (.catch) {
>     let x = .catch.x;
>     let y = .catch.y;
>     ...
>   }
>
> using the PatternRewriter's normal facilities. This has the side benefit
> of throwing the appropriate variable conflict errors for declarations
> made inside the catch block.
>
> No change is made to non-destructured cases, which will hopefully save
> us some work if https://github.com/tc39/ecma262/issues/150 is adopted
> in the spec.
>
> There's one big problem with this patch, which is a lack of PreParser
> support for the redeclaration errors. But it seems we're already lacking
> good PreParser support for such errors, so I'm not sure that should
> block this moving forward.
>
> BUG=v8:811
> LOG=y
>
> Committed: https://crrev.com/a316db995e6e4253664920652ed4e5a38b2caeba
> Cr-Commit-Position: refs/heads/master@{#31797}

TBR=rossberg@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:811

Review URL: https://codereview.chromium.org/1408063013

Cr-Commit-Position: refs/heads/master@{#31798}

The approach is to desugar

  try { ... }
  catch ({x, y}) { ... }

into

  try { ... }
  catch (.catch) {
    let x = .catch.x;
    let y = .catch.y;
    ...
  }

using the PatternRewriter's normal facilities. This has the side benefit
of throwing the appropriate variable conflict errors for declarations
made inside the catch block.

No change is made to non-destructured cases, which will hopefully save
us some work if https://github.com/tc39/ecma262/issues/150 is adopted
in the spec.

There's one big problem with this patch, which is a lack of PreParser
support for the redeclaration errors. But it seems we're already lacking
good PreParser support for such errors, so I'm not sure that should
block this moving forward.

BUG=v8:811
LOG=y

Review URL: https://codereview.chromium.org/1417483014

Cr-Commit-Position: refs/heads/master@{#31797}