IE9PP4 bug reports:
- Crash on ES5 strict mode test page
- clientX/clientY (and pageX/pageY) properties are missing on contextmenu events
Object.freeze(document)
kills consoleconsole.log
typeof is "object" instead of "function"- Some host objects still have "unknown" type
Object.prototype.hasOwnProperty
discrepancy with host objects- Add HTML5 Element::classList