Added example for capturing backtrace of non calling thread

Author: Jardynq

examples/other_thread.rs

@@ -0,0 +1,45 @@
+// Windows only currently
+use std::os::windows::prelude::AsRawHandle;
+use backtrace::{Backtrace, BacktraceFrame};
+
+
+fn worker() {
+    foo();
+}
+fn foo() {
+    bar()
+}
+fn bar() {
+    baz()
+}
+fn baz() {
+    println!("Hello from thread!");
+    // Sleep for simple sync. Can't read thread that has finished running
+    //std::thread::sleep(std::time::Duration::from_millis(1000));
+    loop {
+        print!("");
+    };
+}
+
+
+fn main() {
+    let thread = std::thread::spawn(|| {
+        worker();
+    });
+    let os_handle = thread.as_raw_handle();
+    
+    // Allow the thread to start
+    std::thread::sleep(std::time::Duration::from_millis(100));
+
+    let mut frames = Vec::new();
+    unsafe {
+        backtrace::trace_thread_unsynchronized(os_handle,|frame| {
+            frames.push(BacktraceFrame::from(frame.clone()));
+            true
+        });
+    }
+
+    let mut bt = Backtrace::from(frames);
+    bt.resolve();
+    println!("{:?}", bt);
+}