Remove [GenerateConstructor] from IDL files

Remove [GenerateConstructor] from IDL files
https://bugs.webkit.org/show_bug.cgi?id=77598

Reviewed by Adam Barth.

[GenerateConstructor] is used in some IDL files but it is not implemented
in code generators. I could not find any history about [GenerateConstructor]
in code generators. This patch removes them from IDL files.

Maybe we want to replace [GenerateConstructor] with [Constructor] eventually,
but currently no tests are written for their constructors (e.g. "new DOMTokenList()").
So simply removing them would make sense.

No new tests. No change in behavior.

* dom/DOMStringList.idl:
* html/DOMSettableTokenList.idl:
* html/DOMTokenList.idl:
* svg/SVGFEConvolveMatrixElement.idl:
* webaudio/AudioPannerNode.idl:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@106532 268f45cc-cd09-0410-ab3c-d52691b4dbfc