Merge pull request #337 from lucperkins/adapters-send-sync #571

Job	Run time
build_wasm	1m 5s
build_test (nightly)	1m 42s
build_test (beta)	1m 50s
build_test (stable)	2m 36s
lockfile	1m 52s
clippy_format (stable)	1m 14s
no_features_build_test (nightly)	40s
no_features_build_test (beta)	40s
no_features_build_test (stable)	50s
build_spec (nightly)	1m 32s
build_spec (beta)	1m 37s
build_spec (stable)	1m 46s
	17m 24s

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