IDL compiler: [Custom] special operations

* A few minor Perl changes to regularize include handling
　(so we don't need to special-case [Custom] in Python)
　We did this before for [Custom] attributes; this results in changing 3 bindings: adding V8Node.h to 3, and GetPtr.h/RefPtr.h to 1.
* Reusing existing test case, with 2 minor features commented out;
　will uncomment when implement in follow-up.

BUG=239771
R=haraken

Review URL: https://codereview.chromium.org/134193008

git-svn-id: svn://svn.chromium.org/blink/trunk@166100 bbb929c8-8fbe-4397-9dbb-9b2b20218538