Miri complains about pointer dereferencing in nom_locate

[matzemathics]

The CI on the parser branch currently fails due to miri complaining about a pointer dereference in nom_locate. Specifically, extending a slice backwards to its original size is impossible in the current (experimental) aliasing model checked by miri.

Also note that the violation is not due to unsafe code in the nemo crate -- miri fails on the tests inside nom_locate and even on the example provided in the nom_locate docs, so this is not something we can currently fix.

[matzemathics]

There is some discussion whether such pointer operations should be considered safe: rust-lang/unsafe-code-guidelines#134.

[matzemathics]

Given the small size of the nom_locate crate, I feel I should be able to cook up a solution that satisfies miri pretty quickly.