bump MSRV

1.85.0 adds async closure support and should be two versions older than the
current stable release once this is merged, per Wasmtime's current policy.

Signed-off-by: Joel Dice <joel.dice@fermyon.com>

Author: dicej

Cargo.toml

@@ -176,7 +176,7 @@ authors = ["The Wasmtime Project Developers"]
 edition = "2021"
 # Wasmtime's current policy is that this number can be no larger than the
 # current stable release of Rust minus 2.
-rust-version = "1.84.0"
+rust-version = "1.85.0"
 
 [workspace.lints.rust]
 # Turn on some lints which are otherwise allow-by-default in rustc.

crates/wasmtime/src/runtime/component/concurrent.rs

@@ -2616,6 +2616,9 @@ impl ComponentInstance {
             }
             _ => bail!("invalid task handle: {task_id}"),
         };
+        // Since waitables can neither be passed between instances nor forged,
+        // this should never fail unless there's a bug in Wasmtime, but we check
+        // here to be sure:
         assert_eq!(expected_caller_instance, caller_instance);
         log::trace!("subtask_drop {waitable:?} (handle {task_id})");
         Ok(())
@@ -2644,6 +2647,9 @@ impl ComponentInstance {
             }
             _ => bail!("invalid task handle: {task_id}"),
         };
+        // Since waitables can neither be passed between instances nor forged,
+        // this should never fail unless there's a bug in Wasmtime, but we check
+        // here to be sure:
         assert_eq!(expected_caller_instance, caller_instance);
 
         log::trace!("subtask_cancel {waitable:?} (handle {task_id})");