Add Open Codefix does not work for operators

[cartermp]

Using RC4, enter the following in an F# script file:

module MyOps =
    let (>.>) x f = f(x)

let bananas xs =
    xs >.> List.map (fun x -> "bananas")

Expected: Lightbulb comes up, offering to open MyOps.

Actual: No lightbulb.

Note that this affects libraries such as Suave, where you need to open the Suave.Operators namespace to compose routes, and it's not always obvious to people that this is the case.

[cartermp]

I can get it to trigger by adding FS0043 to the list of fixableDiagnosticIds. Looks like this:

The latter option actually causes the code to fail to compile because it's treated just as a regular function call. That suggestion could get filtered in this case, I guess.

@vasily-kirichenko any concerns about recognizing FS0043?

[vasily-kirichenko]

@cartermp looks like a good fix.