stoically authored May 07, 2020 and Hubert Chathi committed May 07, 2020

Allows building an WASM-ready archive with emscripten.

This allows e.g. to compile to the `wasm32-unknown-unknown`
target with Rust.

Related matrix-rust-sdk PR:
https://github.com/matrix-org/matrix-rust-sdk/pull/31



Signed-off-by: stoically <stoically@protonmail.com>