Restore visitLabelElement() and visitLocalVariableElement().

Restore visitLabelElement() and visitLocalVariableElement().


Revert "Remove visitLabelElement() and visitLocalVariableElement()."

This reverts commit 2c064df1451568d4b1187b9a54d0ad7cc383612e.

R=brianwilkerson@google.com, paulberry@google.com
BUG=

Committed: https://github.com/dart-lang/sdk/commit/51b50f771080b450228300e08e837fbe3dd97eb4

[jwren, 2017-07-10 17:58:04]

On 2017/07/10 17:56:37, scheglov wrote:

LGTM

[scheglov, 2017-07-10 18:00:32]

Description was changed from

==========
Restore visitLabelElement() and visitLocalVariableElement().


Revert "Remove visitLabelElement() and visitLocalVariableElement()."

This reverts commit 2c064df1451568d4b1187b9a54d0ad7cc383612e.

R=brianwilkerson@google.com, paulberry@google.com
BUG=
==========

to

==========
Restore visitLabelElement() and visitLocalVariableElement().


Revert "Remove visitLabelElement() and visitLocalVariableElement()."

This reverts commit 2c064df1451568d4b1187b9a54d0ad7cc383612e.

R=brianwilkerson@google.com, paulberry@google.com
BUG=

Committed:
https://github.com/dart-lang/sdk/commit/51b50f771080b450228300e08e837fbe3dd97eb4
==========

[scheglov, 2017-07-10 18:00:35]

Committed patchset #1 (id:1) manually as
51b50f771080b450228300e08e837fbe3dd97eb4 (presubmit successful).

[Brian Wilkerson, 2017-07-19 16:32:10]

lgtm, but out of curiosity, what was the motivation for reverting?

[Paul Berry, 2017-07-19 16:38:22]

On 2017/07/19 16:32:10, Brian Wilkerson wrote:
> lgtm, but out of curiosity, what was the motivation for reverting?

There was client code (part of Kythe support) that was visiting local variable
elements and label elements in order to generate identifiers for them.

When we removed these visit methods in 2c064df1451568d4b1187b9a54d0ad7cc383612e
we thought that visitors would no longer ever encounter local variable elements
and label elements.  But that was because we were only thinking about recursive
visitors that walk through the element model from the top down.  The visitors in
the Kythe logic start from a resolved AST, follow the pointer from the resolved
AST to the element, and then visit the element to generate its ID.

[scheglov, 2017-07-19 16:39:35]

On 2017/07/19 16:32:10, Brian Wilkerson wrote:
> lgtm, but out of curiosity, what was the motivation for reverting?

Internal code indexer uses Element.accept(indexingElementVisitor) to process
different types of elements in different visitX() methods.
It does not need to visit local variables or labels recursively, just type
switch.