Implement the intrinsic in Miri

Author: saethlin

src/tools/miri/src/shims/intrinsics/mod.rs

@@ -425,6 +425,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 throw_machine_stop!(TerminationInfo::Abort(format!("trace/breakpoint trap")))
             }
 
+            "debug_assertions" => {
+                let [] = check_arg_count(args)?;
+                this.write_scalar(Scalar::from_bool(this.tcx.sess.opts.debug_assertions), dest)?;
+            }
+
             name => throw_unsup_format!("unimplemented intrinsic: `{name}`"),
         }