add type="built-in function"

[bakkot]

cf tc39/ecma262#3748 (comment)

That this does not include support for built-in getters/setters, nor for non-function properties. I can add those too if we want I guess, but they'd be handled differently since they do not have parameter lists.

I have a branch of ecma262 which adds type="built-in function" to all the relevant clauses (I think), which I have tested this against.

[jmdyck]

That this does not include support for built-in getters/setters, nor for non-function properties. I can add those too if we want I guess, but they'd be handled differently since they do not have parameter lists.

For another reason to handle them differently, consider, e.g., 22.2.6.3 get RegExp.prototype.dotAll. The section title suggests that the section is only about the get accessor function. But the preamble tells you that the set accessor function is undefined, so in fact the section is about both accessor functions, i.e. the whole accessor property, and it would be misleading for the section's type attribute to be "built-in function".