dev-util/xxdi is a lightweight alternative to app-editors/vim-core. dev-libs/rocr-runtime-3.7.0 should probably depend on either one.
If you want to submit a PR to conditionally use dev-util/xxdi instead of app-editors/vim-core, I'd consider it.
-> https://github.com/gentoo/gentoo/pull/17254
According to the script in rocr-runtime only "xxd" will be used. Unless we patch it, rocr-runtime won't use xxd.pl from dev-util/xxdi. Since dev-util/xxdi isn't a drop in replacement, I'm not doing to make the change suggested here. However, if you want to do so and provide the a PR, please go ahead and I'll absolutely consider merging it. Thank you!