inspector: include node_platform.h header

[alexeykuzmin]

When Node.js is compiled as a part of the Electron build clang generates a couple of errors (see below). Including a header instead of using a forward declaration fixes them.
It would be great if the code could be changed in the Node.js repo so Electron wouldn't have to have a patch for that.

../../vendor/node/src/inspector_agent.cc:516:16: error: member access into incomplete type 'node::NodePlatform' platform_->FlushForegroundTasksInternal(); ^ ../../vendor/node/src/inspector_agent.h:19:7: note: forward declaration of 'node::NodePlatform' class NodePlatform; ^ ../../vendor/node/src/inspector_agent.cc:670:15: error: assigning to 'v8::Platform *' from incompatible type 'node::NodePlatform *' platform_ = platform; ^~~~~~~~ 2 errors generated. 

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

Affected core subsystem(s)

inspector

[gireeshpunathil]

CI: https://ci.nodejs.org/job/node-test-pull-request/11169/

[alexeykuzmin]

@gireeshpunathil Is it normal that CI jobs are in the pending state for almost 3 days already?

[gireeshpunathil]

@alexeykuzmin - actually the CI has been completed in time, but the view in github is not updated to reflect that fact - probably a bug - @nodejs/collaborators - please share any prior art on this if you know.

Landed in 916e1cb , thanks for the contribution!

[Trott]

please share any prior art on this if you know.

Yeah, bug in the bot used to update that stuff. I think @maclover7 recently fixed it or was working on fixing it.

[maclover7]

@gireeshpunathil@Trott Build statuses should be reporting properly for all node-test-pull-request builds started after ~noon EST yesterday. If there are PRs you would like to backfill statuses for, I should be able to do that, ping me on IRC :)