Undefined is not a literal.

There is no undefined Literal.

BUG=
R=rossberg@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=15724

[oliv, 2013-07-11 13:04:22]

as +rossberg pointed out, undefined can be locally reassigned

[rossberg, 2013-07-11 13:55:49]

On 2013/07/11 13:04:22, oliv wrote:
> as +rossberg pointed out, undefined can be locally reassigned

I'd prefer to keep IsUndefinedLiteral as an abstraction and simply change its
implementation.

[oliv, 2013-07-12 13:19:35]

On 2013/07/11 13:55:49, rossberg wrote:
> On 2013/07/11 13:04:22, oliv wrote:
> > as +rossberg pointed out, undefined can be locally reassigned
> 
> I'd prefer to keep IsUndefinedLiteral as an abstraction and simply change its
> implementation.

ok, PTAL

[rossberg, 2013-07-12 13:40:32]

LGTM with comments

https://codereview.chromium.org/18429005/diff/16001/src/ast.cc
File src/ast.cc (right):

https://codereview.chromium.org/18429005/diff/16001/src/ast.cc#newcode76
src/ast.cc:76: VariableProxy* var_proxy = static_cast<VariableProxy*>(this);
Instead of these two lines, use AsVariableProxy() and return false if it's NULL.

https://codereview.chromium.org/18429005/diff/16001/src/ast.cc#newcode81
src/ast.cc:81: strncmp(*var_proxy->name()->ToCString(), "undefined", 10) == 0;
You should be able to say

  var->name()->Equals(isolate()->heap()->undefined_string())

especially since that will take advantage of the string internalization the
parser performs.

[oliv, 2013-07-17 14:10:44]

Committed patchset #5 manually as r15724 (presubmit successful).