Incorrect "unresolved import" in std

[hghwng]

To reproduce the bug, just enter the following code under Linux:

use std::os::unix::io::AsRawFd;
fn main() {}

RA emits the error of "unresolved import". Since the block is conditionally compiled with cfg_if (see the source of std), I suspect that the guard is not handled correctly.

Enabling loadOutDirsFromCheck and procMacro does not solve the problem.

[bjorn3]

Duplicate of #6038