Add support for type parameters

[dominikh]

No description provided.

[muirdm]

I was looking at this, at least in terms of font locking. For ambiguous cases like foo[bar](baz) do you think we should assume it is a generic function instantiation and treat "bar" as a type, or leave it as-is?

[dominikh]

I say we leave it as is.

[muirdm]

Beyond #400, the only other thing I'm aware of for fontification is fontifying function calls and composite literal type names properly in foo[int](123) and some.Struct[int]{foo: bar}. Anything else?

[dominikh]

I'm the wrong person to ask about fontification, I barely use any. But I'd like to err on the side of "no fontification" over "wrong fontification". So since we lack type info, we can't do anything for foo[int](123).