Rollup merge of #96725 - nico-abram:win_tid, r=ChrisDenton

Expose process windows_process_extensions_main_thread_handle on Windows

~~I did not find any tests in https://github.com/rust-lang/rust/blob/7d3e03666a93bd2b0f78b3933f9305832af771a5/library/std/src/sys/windows/process/tests.rs that actually launch processes, so I haven't added tests for this.~~ I ran the following locally, to check that it works as expected:
```rs
#![feature(windows_process_extensions_main_thread_handle)]

fn main() {
    use std::os::windows::process::{ChildExt, CommandExt};
    const CREATE_SUSPENDED: u32 = 0x00000004;

    let proc = std::process::Command::new("cmd")
        .args(["/C", "echo hello"])
        .creation_flags(CREATE_SUSPENDED)
        .spawn()
        .unwrap();

    extern "system" {
        fn ResumeThread(_: *mut std::ffi::c_void) -> u32;
    }
    unsafe {
        ResumeThread(proc.main_thread_handle());
    }

    let output = proc.wait_with_output().unwrap();
    let str_output = std::str::from_utf8(&output.stdout[..]).unwrap();
    println!("{}", str_output);
}

```

Without the feature attribute it wouldn't compile, and commenting the `ResumeThread` line makes it hang forever, showing that it works.

Trakcing issue https://github.com/rust-lang/rust/issues/96723

1 files changed, 25 insertions, 0 deletions

diff --git a/library/std/src/sys/windows/process/tests.rs b/library/std/src/sys/windows/process/tests.rs
index be3a0f4ed52..3fc0c75240c 100644
--- a/library/std/src/sys/windows/process/tests.rs
+++ b/library/std/src/sys/windows/process/tests.rs
@@ -25,6 +25,31 @@ fn test_raw_args() {
 }
 
 #[test]
+fn test_thread_handle() {
+    use crate::os::windows::io::BorrowedHandle;
+    use crate::os::windows::process::{ChildExt, CommandExt};
+    const CREATE_SUSPENDED: u32 = 0x00000004;
+
+    let p = Command::new("cmd").args(&["/C", "exit 0"]).creation_flags(CREATE_SUSPENDED).spawn();
+    assert!(p.is_ok());
+    let mut p = p.unwrap();
+
+    extern "system" {
+        fn ResumeThread(_: BorrowedHandle<'_>) -> u32;
+    }
+    unsafe {
+        ResumeThread(p.main_thread_handle());
+    }
+
+    crate::thread::sleep(crate::time::Duration::from_millis(100));
+
+    let res = p.try_wait();
+    assert!(res.is_ok());
+    assert!(res.unwrap().is_some());
+    assert!(p.try_wait().unwrap().unwrap().success());
+}
+
+#[test]
 fn test_make_command_line() {
     fn test_wrapper(prog: &str, args: &[&str], force_quotes: bool) -> String {
         let command_line = &make_command_line(