util: Format negative zero as '-0'

[divec]

Format negative zero as '-0' instead of as '0', as it does not behave
identically to positive zero. ((-0).toString() still returns '0' as
required by ES5 9.8.1.2).

Fixes #6548

[Nodejs-Jenkins]

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[TooTallNate]

Seems good to me at first glance. You'll need to add a test, and sign the CLA.

[divec]

Thanks, have signed the CLA

[TooTallNate]

@isaacs @tjfontaine et all. What do you guys think? Bug fix and hence v0.10 branch, or new functionality and hence master branch? I could see it going either way really.

[divec]

I'd love to see it in v0.10, but I should point out that Chromium and Firebug format -0 as '0' so it's hard for me to claim that the existing behaviour is actually 'wrong' per se.

[skenqbx]

@divec Since when can zero be negative?

[juliangruber]

http://en.wikipedia.org/wiki/Signed_zero

[rlidwka]

Since when can zero be negative?

Since 1985.

[skenqbx]

@juliangruber thx for clarification
@rlidwka gg

[TooTallNate]

So it looks like the Chromium guys are moving ahead with this one: https://codereview.chromium.org/82553008/

I'm kinda leaning towards master branch at this point, but not really for any particular reason.

[rlidwka]

It is master branch. Although it's extremely unlikely that someone would depend on it, it's not a bugfix, and it changes behaviour of util module.

[TooTallNate]

Thanks @divec. Landed in b3e4fc6 on master branch. Note that I had to update the email address on the commit to match the one you used to sign the CLA.