Make visualizer robust to graphs with NULL inputs.

Make visualizer robust to graphs with NULL inputs.

R=mstarzinger@chromium.org, jarin@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=25084

[titzer, 2014-11-03 13:20:05]

On 2014/10/14 13:12:30, titzer wrote:

PTAL, I've updated this CL to use a queue in the visualizers and removed my
hackage to generic-algorithm.

[Michael Starzinger, 2014-11-03 17:16:42]

mstarzinger@chromium.org changed reviewers:
+ mstarzinger@chromium.org

[Michael Starzinger, 2014-11-03 17:16:43]

LGTM (mostly rubber-stamped).

https://codereview.chromium.org/652263002/diff/20001/test/cctest/compiler/tes...
File test/cctest/compiler/test-graph-visualizer.cc (right):

https://codereview.chromium.org/652263002/diff/20001/test/cctest/compiler/tes...
test/cctest/compiler/test-graph-visualizer.cc:87: phi->ReplaceInput(1, NULL);
nit: It doesn't seem like this phi is reachable from start. Maybe use a Merge
instead if a Phi here.

[titzer, 2014-11-03 17:40:09]

On 2014/11/03 17:16:43, Michael Starzinger wrote:
> LGTM (mostly rubber-stamped).
> 
>
https://codereview.chromium.org/652263002/diff/20001/test/cctest/compiler/tes...
> File test/cctest/compiler/test-graph-visualizer.cc (right):
> 
>
https://codereview.chromium.org/652263002/diff/20001/test/cctest/compiler/tes...
> test/cctest/compiler/test-graph-visualizer.cc:87: phi->ReplaceInput(1, NULL);
> nit: It doesn't seem like this phi is reachable from start. Maybe use a Merge
> instead if a Phi here.

Done.

[titzer, 2014-11-03 17:42:03]

Committed patchset #2 (id:20001) manually as 25084 (presubmit successful).