Rollup merge of #79998 - devsnek:wasm32-bindgen-compat, r=alexcrichton
Rollup merge of #79998 - devsnek:wasm32-bindgen-compat, r=alexcrichton

Use correct ABI for wasm32 by default

Introduces `wasm32-unknown-bindgen` for those wishing to use the bindgen compat abi. `wasm32-*` now uses the correct abi by default.

Fixes https://github.com/rustwasm/team/issues/291

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