Rollup merge of #146800 - thaliaarchi:fix-move-pal-thread, r=joboet

Fix unsupported `std::sys::thread` after move

Fixes building std for any platform with an unsupported thread abstraction. This includes {aarch64,armv7,x86_64}-unknown-trusty and riscv32im-risc0-zkvm-elf, which explicitly include the unsupported module, and platforms with no PAL.

Bug fix for #145177 (std: move thread into sys).

Also fix the `std` build for xtensa, which I incidentally found while looking for an unsupported platform.

r? `@joboet`

Author: matthiaskrgr

library/core/src/ffi/va_list.rs

@@ -2,6 +2,7 @@
 //!
 //! Better known as "varargs".
 
+#[cfg(not(target_arch = "xtensa"))]
 use crate::ffi::c_void;
 #[allow(unused_imports)]
 use crate::fmt;

library/std/src/sys/env_consts.rs

@@ -2,7 +2,7 @@
 
 // Replaces the #[else] gate with #[cfg(not(any(…)))] of all the other gates.
 // This ensures that they must be mutually exclusive and do not have precedence
-// like cfg_if!.
+// like cfg_select!.
 macro cfg_unordered(
     $(#[cfg($cfg:meta)] $os:item)*
     #[else] $fallback:item

library/std/src/sys/pal/trusty/mod.rs

@@ -7,8 +7,6 @@ mod common;
 pub mod os;
 #[path = "../unsupported/pipe.rs"]
 pub mod pipe;
-#[path = "../unsupported/thread.rs"]
-pub mod thread;
 #[path = "../unsupported/time.rs"]
 pub mod time;
 

library/std/src/sys/pal/unsupported/mod.rs

@@ -2,7 +2,6 @@
 
 pub mod os;
 pub mod pipe;
-pub mod thread;
 pub mod time;
 
 mod common;

library/std/src/sys/pal/zkvm/mod.rs

@@ -14,8 +14,6 @@ pub mod abi;
 pub mod os;
 #[path = "../unsupported/pipe.rs"]
 pub mod pipe;
-#[path = "../unsupported/thread.rs"]
-pub mod thread;
 #[path = "../unsupported/time.rs"]
 pub mod time;
 

library/std/src/sys/process/unix/vxworks.rs

@@ -4,8 +4,7 @@ use libc::{self, RTP_ID, c_char, c_int};
 use super::common::*;
 use crate::io::{self, ErrorKind};
 use crate::num::NonZero;
-use crate::sys::cvt;
-use crate::sys::pal::thread;
+use crate::sys::{cvt, thread};
 use crate::{fmt, sys};
 
 ////////////////////////////////////////////////////////////////////////////////