CheckDeclarations: don't report environment for checked top-level module

[auduchinok]

Fixes completion for Field field at the caret position:

type Record =
    { Field: int }

{ Fie{caret} }

Prior to this change, another name environment for the anon module is reported after it's been checked, and this environment overwrites an environment that should've been used inside the module. Reporting such an environment is needed for analysis of subsequent module declarations in the outer scope but breaks editor features inside top-level modules when reported for its own range.

[auduchinok]

OK, the failing test shows an actual regression related to recursive modules. I'm looking into it.

[auduchinok]

Hm, for some reason CI doesn't restart on PR reopening...

[vzarytovskii]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[auduchinok]

@DedSec256 @vzarytovskii Do you have any idea why xml doc tests could fail in this PR?

[vzarytovskii]

Huh, that's some weird failures. It does not ring a bell to me, I will try to figure it out tomorrow morning.

Edit: it also seems to be failing for the same reason in #12872

[auduchinok]

It's ready.