`SynType.Tuple` doesn't include leading parameter names and attributes in signatures

[auduchinok]

type T =
    member M: p1: a * p2: b -> int

Ast. It seems previously names and attributes were included, as we used the tuple type range field to find where parameter signature starts.

cc @nojaf

[nojaf]

Being devil's advocate here, if the type is not in a tuple it also isn't included in the SynType range.

Example

SynType.App doesn't contains p0.

Aren't we missing a better representation in SynType in the case a name is present?
Would this also not simplify a lot of things?
I'm guessing you also need to piece together the SynValInfo with the correct SynType to get the information you are really after.

Looking at implementation, it uses SynPat.Typed to cover this case.
Could we also not have a counterpart for SynType?

//cc @dsyme

[nojaf]

Proposal:

Fixing the bug first as is.
And in a future PR I'd like to have something like:

type SynType =
    ...
    | Named of attributes: SynAttributes * qmark: range option * id: SynIdent * usedType: SynType * range: range

to represent a: t