Rust

Report more specific errors for unknown constants #454

Job	Run time
coverage	1m 15s
Build fuzz targets	1m 8s
bench	1m 17s
build (ubuntu-latest, stable)	55s
build (ubuntu-latest, beta)	52s
cross (i686-unknown-linux-gnu)	47s
doc	23s
build (ubuntu-latest, nightly)	53s
cross (powerpc64-unknown-linux-gnu)	57s
features	3m 9s
build (ubuntu-latest, 1.65.0)	2m 33s
build (stable, macOS-latest)	49s
msrv-read	1m 51s
rustfmt	6s
Run `debug_abbrev` fuzz target	5m 6s
Run `debug_aranges` fuzz target	5m 5s
Run `debug_info` fuzz target	5m 6s
Run `debug_line` fuzz target	5m 7s
Run `eh_frame` fuzz target	5m 6s
Run `eh_frame_hdr` fuzz target	5m 10s
	47m 35s

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