The wasm32 branch of libstd never works


#1

Hi,

I’m trying to compile program with cargo build --target=wasm32-unknown-emscripten --all. And the UnsafeCell fallback of RwLock and Mutex in the wasm32 implementation of libstd helps a lot in my scenario.

But it seems that the wasm32 branch never works due to https://github.com/rust-lang/rust/blob/8b7f164eab538025a29488e2e47ae7b4bbee2ad9/src/libstd/sys/mod.rs#L35. Is this the desired behavior?