minor rt cleanup

Author: bblum

src/rt/rust_task.cpp

@@ -574,15 +574,6 @@ sp_in_stk_seg(uintptr_t sp, stk_seg *stk) {
     return (uintptr_t)stk->data <= sp && sp <= stk->end;
 }
 
-struct reset_args {
-    rust_task *task;
-    uintptr_t sp;
-};
-
-void
-reset_stack_limit_on_c_stack(reset_args *args) {
-}
-
 /*
 Called by landing pads during unwinding to figure out which stack segment we
 are currently running on and record the stack limit (which was not restored

src/rt/rust_task.h

@@ -433,7 +433,7 @@ rust_task::call_on_rust_stack(void *args, void *fn_ptr) {
 
     bool had_reentered_rust_stack = reentered_rust_stack;
     {
-        // FIXME (#2875) This must be racy. Figure it out.
+        // FIXME (#1868) This must be racy. Figure it out.
         scoped_lock with(lifecycle_lock);
         reentered_rust_stack = true;
     }