Fix Windows CI: cast function pointer through *const () to satisfy function_casts_as_integer lint, allow cast_possible_truncation on i686

Agent-Logs-Url: https://github.com/acl-dev/open-coroutine/sessions/4afcc93e-28af-4537-a925-c2ca02300c75

Co-authored-by: loongs-zhang <38336731+loongs-zhang@users.noreply.github.com>

Author: Copilot

core/src/monitor.rs

@@ -430,7 +430,7 @@ impl Monitor {
             // then set RIP to the preempt assembly function
             context.Rsp -= 8;
             std::ptr::write(context.Rsp as *mut u64, context.Rip);
-            context.Rip = preempt_asm as usize as u64;
+            context.Rip = preempt_asm as *const () as usize as u64;
             if SetThreadContext(thread_handle, &raw const context) == 0 {
                 let _ = ResumeThread(thread_handle);
                 return false;
@@ -462,7 +462,10 @@ impl Monitor {
             // then set EIP to the preempt assembly function
             context.Esp -= 4;
             std::ptr::write(context.Esp as *mut u32, context.Eip);
-            context.Eip = preempt_asm as usize as u32;
+            #[allow(clippy::cast_possible_truncation)]
+            {
+                context.Eip = preempt_asm as *const () as usize as u32;
+            }
             if SetThreadContext(thread_handle, &raw const context) == 0 {
                 let _ = ResumeThread(thread_handle);
                 return false;