Fix wasm32-unknown-emscripten build of corelib

There's an implicit dependency to instant, which in turn requires a patch
to work around rust-lang/rust#67782

Cargo.toml

@@ -25,3 +25,7 @@ members = [
     'tests/driver_lib',
     'tests/rustdriver'
 ]
+
+# Needed to work around wasm32-unknown-emscripten toolchain aborting on cdylib crates
+[patch.crates-io]
+instant = { git = "https://github.com/sixtyfpsui/instant" }