read: use const generics in `src/read/util.rs` #548

Job	Run time
msrv	1m 6s
msrv-read	57s
coverage	1m 5s
Build fuzz targets	1m 2s
build (ubuntu-latest, stable)	51s
bench	1m 7s
build (ubuntu-latest, beta)	44s
cross (i686-unknown-linux-gnu)	39s
build (ubuntu-latest, nightly)	41s
doc	22s
cross (powerpc64-unknown-linux-gnu)	49s
build (stable, macOS-latest)	42s
features	3m 5s
rustfmt	5s
Run `debug_abbrev` fuzz target	5m 6s
Run `debug_aranges` fuzz target	5m 11s
Run `debug_info` fuzz target	5m 6s
Run `debug_line` fuzz target	5m 5s
Run `eh_frame` fuzz target	5m 5s
Run `eh_frame_hdr` fuzz target	5m 6s
	43m 54s

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