[TurboFan] Avoid Gcc compilation fail by Initializing rest_index variable.

[TurboFan] Avoid Gcc compilation fail by Initializing rest_index variable.

  The CL #38858 (https://codereview.chromium.org/2269293004) removed the parameter assignment code
  in rest_parameter(int* index) function in Class DeclarationScope.

  This caused the Gcc compilation fail at the following code in src/compiler/ast-graph-builder.cc, line 576.
  int rest_index;
  Variable* rest_parameter = scope->rest_parameter(&rest_index);
  BuildRestArgumentsArray(rest_parameter, rest_index);

  The error message was:
  ../src/compiler/ast-graph-builder.cc: In member function ‘void v8::internal::compiler::AstGraphBuilder::CreateGraphBody(bool)’:
  ../src/compiler/ast-graph-builder.cc:578:54: error: ‘rest_index’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  BuildRestArgumentsArray(rest_parameter, rest_index);
                                                      ^

  This CL fixed this issue by intializing rest_index to 0.

BUG=

Committed: https://crrev.com/ce1386697f20e49daa424594dc905f2a4f1ddc0d
Cr-Commit-Position: refs/heads/master@{#38863}

[zhengxing.li, 2016-08-24 10:41:21]

zhengxing.li@intel.com changed reviewers:
+ bmeurer@chromium.org, titzer@chromium.org, verwaest@chromium.org,
weiliang.lin@intel.com

[zhengxing.li, 2016-08-24 10:41:22]

PTAL, thanks!

[titzer, 2016-08-24 10:42:06]

lgtm

[zhengxing.li, 2016-08-24 10:43:00]

The CQ bit was checked by zhengxing.li@intel.com

[commit-bot: I haz the power, 2016-08-24 10:43:04]

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, 2016-08-24 11:06:23]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-08-24 11:06:50]

Description was changed from

==========
[TurboFan] Avoid Gcc compilation fail by Initializing rest_index variable.

  The CL #38858 (https://codereview.chromium.org/2269293004) removed the
parameter assignment code
  in rest_parameter(int* index) function in Class DeclarationScope.

  This caused the Gcc compilation fail at the following code in
src/compiler/ast-graph-builder.cc, line 576.
  int rest_index;
  Variable* rest_parameter = scope->rest_parameter(&rest_index);
  BuildRestArgumentsArray(rest_parameter, rest_index);

  The error message was:
  ../src/compiler/ast-graph-builder.cc: In member function ‘void
v8::internal::compiler::AstGraphBuilder::CreateGraphBody(bool)’:
  ../src/compiler/ast-graph-builder.cc:578:54: error: ‘rest_index’ may be used
uninitialized in this function [-Werror=maybe-uninitialized]
  BuildRestArgumentsArray(rest_parameter, rest_index);
                                                      ^

  This CL fixed this issue by intializing rest_index to 0.

BUG=
==========

to

==========
[TurboFan] Avoid Gcc compilation fail by Initializing rest_index variable.

  The CL #38858 (https://codereview.chromium.org/2269293004) removed the
parameter assignment code
  in rest_parameter(int* index) function in Class DeclarationScope.

  This caused the Gcc compilation fail at the following code in
src/compiler/ast-graph-builder.cc, line 576.
  int rest_index;
  Variable* rest_parameter = scope->rest_parameter(&rest_index);
  BuildRestArgumentsArray(rest_parameter, rest_index);

  The error message was:
  ../src/compiler/ast-graph-builder.cc: In member function ‘void
v8::internal::compiler::AstGraphBuilder::CreateGraphBody(bool)’:
  ../src/compiler/ast-graph-builder.cc:578:54: error: ‘rest_index’ may be used
uninitialized in this function [-Werror=maybe-uninitialized]
  BuildRestArgumentsArray(rest_parameter, rest_index);
                                                      ^

  This CL fixed this issue by intializing rest_index to 0.

BUG=

Committed: https://crrev.com/ce1386697f20e49daa424594dc905f2a4f1ddc0d
Cr-Commit-Position: refs/heads/master@{#38863}
==========

[commit-bot: I haz the power, 2016-08-24 11:06:53]

Patchset 1 (id:??) landed as
https://crrev.com/ce1386697f20e49daa424594dc905f2a4f1ddc0d
Cr-Commit-Position: refs/heads/master@{#38863}