Replace `mips_shared` with `mips64` and simplify `DEFINED_ON` to use `PER_SHARED_ARCH` or `PER_ARCH` when possible. (This requires to add wasm32 stubs in some cases.) Differential Revision: https://phabricator.services.mozilla.com/D238083
Replace `mips_shared` with `mips64` and simplify `DEFINED_ON` to use `PER_SHARED_ARCH` or `PER_ARCH` when possible. (This requires to add wasm32 stubs in some cases.) Differential Revision: https://phabricator.services.mozilla.com/D238083