Selectively use Object.defineProperty if it is available.

[mcollina]

Do not merge, as it missing #298.

@ScottFreeCode can you confirm this is working for you?

Fixes #301

[calvinmetcalf]

good if green

[mcollina]

I will update when 8.1.3 comes out.

[ScottFreeCode]

Tried pulling this in by using "nodejs/readable-stream#maybe-ie7-ie8" as "readable-stream"; seems to have fixed IE 7, but we've still got some issue with IE 8 and it's not showing the line number from the original file (or even which file was the original); let me talk to the team lead about getting access to some kind of cache or artifact upload of the browser bundle so we can try to determine what that line is...

[mcollina]

@ScottFreeCode you might be more familiar with IE 8 than me, can you confirm this is the correct way to detect if we are running on IE8? I need to disable it even though it is present.

[ScottFreeCode]

Looks right as far as I'm aware; document.documentMode is 11 on the last IE unless I fiddle with the compatibility mode, in which case it becomes 8 on compatibility mode for IE 8. Moreover, the fix did seem to work for IE7, which is even lower.

Running this bit of code (the if condition with !maybeDefineProperty replaced with !Object.defineProperty) in compatibility mode for 7, 8 and 9 got true for 7 and 8 and false for 9.

There's always brute-force try-catch-based feature sniffing to deal with the fact that IE 8 has the function but it doesn't work right; but that would probably be overkill considering this works fine as far as I can tell.

[mcollina]

the problem is that it is not working as expected. The error you are seeing is due to IE 8 broken Object.defineProperty. Something in that bit of logic is wrong. I would not like to use the try-catch approach.