Add an efficient implementation based on critical-section #851

Job	Run time
loom	43s
miri	3m 56s
clippy	26s
fmt	12s
msrv	29s
security_audit	4s
test (stable)	1m 18s
test (beta)	1m 28s
test (nightly)	1m 19s
test (nightly, i686-unknown-linux-gnu)	1m 40s
	11m 35s

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