Standardize x-mac-greek, x-mac-centraleurroman, and x-mac-turkish

[annevk]

WebKit still supports these encodings and is reluctant to remove them as it would more likely negatively impact end users than improve matters. As they are all straightforward single-byte encodings would there be interest from others on adding these to the web platform?

They are conveniently documented on Wikipedia:

• https://en.wikipedia.org/wiki/MacGreek_encoding
• https://en.wikipedia.org/wiki/Mac_OS_Central_European_encoding
• https://en.wikipedia.org/wiki/Mac_OS_Turkish_encoding

cc @hsivonen @inexorabletash

[inexorabletash]

Can you point to web content that's failing due to lack of support?

@ricea may have opinions here.

[ricea]

I'm opposed to supporting more legacy encodings. It undermines our push to get everyone on UTF-8.

In this case, the encodings have been obsolete for 20 years, and I can't find any demand from users to support them.

I honestly doubt anyone would notice if WebKit removed support.

[hsivonen]

I don't recall seeing demand for these encodings for Web compat purposes, so I think we shouldn't be adding these. I don't recall seeing evidence of x-mac-cyrillic needing to be in the Encoding Standard for Web compat.

(I observe that Safari does not have Mac OS Turkish or MacGreek in its encoding menu though it does have the Roman, Korean, Cyrillic, and Central European legacy Mac OS encodings.)