std net test `base_port` logic seems strange/outdated?

[jieyouxu]

I was running ./x test library/std --stage 0 locally, and a bunch of std TCP tests were failing because apparently my VPN software is already using one of the ports that the TCP tests were trying to use (this part is user issue).

However, while reading the tests it seems like base_port (which I think is transitively used by TCP tests) is doing some kind of... CI job detection? Which has been outdated for many years? Not sure what this is supposed to be.

rust/library/std/src/net/test.rs

Lines 34 to 60 in 5958825

	// The bots run multiple builds at the same time, and these builds
	// all want to use ports. This function figures out which workspace
	// it is running in and assigns a port range based on it.
	fn base_port() -> u16 {
	let cwd = if cfg!(target_env = "sgx") {
	String::from("sgx")
	} else {
	env::current_dir().unwrap().into_os_string().into_string().unwrap()
	};
	let dirs = [
	"32-opt",
	"32-nopt",
	"musl-64-opt",
	"cross-opt",
	"64-opt",
	"64-nopt",
	"64-opt-vg",
	"64-debug-opt",
	"all-opt",
	"snap3",
	"dist",
	"sgx",
	];
	dirs.iter().enumerate().find(|&(_, dir)| cwd.contains(dir)).map(|p| p.0).unwrap_or(0) as u16
	* 1000
	+ 19600
	}

[jieyouxu]

AFAIK this was never modified since std::net was initially introduced: 395709c#diff-17da68d347d26436e1dd59334284f2de7102367c69c25314112b39d602ea5043. Not sure what this is supposed to do.