Check expressions: safer init properties check

[auduchinok]

Fixes #13857.

[vzarytovskii]

Huh, interesting, I've introduced it in #13490, not sure why I've used List.head though.
Probably just because it is used for properties:
https://github.com/dotnet/fsharp/pull/13490/files#diff-abbd2e67118d1b130339772eb817cfeba41f4a56819c69d551049aa949689b61R9045

@auduchinok did you manage to get a smaller repro? Do we know on which code is it throwing?

[auduchinok]

@auduchinok did you manage to get a smaller repro? Do we know on which code is it throwing?

Nope, it started throwing it on a big solution at some point, so I went to look at the code that throws it.
I've verified the fix on the tests mentioned in #13857, though.