gopls: group comments for hover

[mateusz834]

While looking at the compiler source, i noticed that the
hover results of cmd/compile/internal/ir.Op are pretty bad.
First of all currently the preference order is like this:
spec.Doc, decl.Doc, spec.Comment. I don't understand why
we prefer decl.Doc over spec.Comment, but at the same time
i also wonder why we do not show both spec.Comment and
spec.Doc in the hover result.

But getting to the point: While looking at the ir.Op
i noticed that we do not really have a way to detect
group comments (comments that reference few constants),
some Doc comments of ir.Op are group comments, some others
are not.

This change tries to address that, by introducing of a
concept of a group comment, see examples in the added test
to get an idea how it works.

[gopherbot]

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[gopherbot]

Message from Mateusz Poliwczak:

Patch Set 1:

(1 comment)

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