No longer put wasm condvars in a box.
No longer put wasm condvars in a box.

These condvars are just an AtomicUsize, so can be moved without
problems.

graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust