fix(primitives) : Check first byte for EOF #3547

Job	Run time
check no-default-features	16s
check serde	27s
check std	20s
clippy	1m 23s
test stable --no-default-features	57s
test stable	55s
test stable --all-features	1m 32s
test no_std	25s
test beta --no-default-features	59s
test beta	54s
docs	1m 17s
fmt	7s
test beta --all-features	1m 31s
test nightly --no-default-features	54s
test nightly	45s
test nightly --all-features	1m 20s
	14m 2s

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