Shrink code produced by `smallvec![]`. #249

Job	Run time
no_std	15s
Build/Test (stable, ubuntu-latest)	24s
Build/Test (nightly, ubuntu-latest)	2m 47s
Build/Test (beta, ubuntu-latest)	26s
Build/Test (1.36.0, ubuntu-latest)	2m 12s
Build/Test (windows-latest, nightly)	2m 34s
Result	2s
	8m 40s

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