Yes, the pointer issues Ralf raises has implications about what operations Rust can make safe. An example Ralf posed to the safe transmute working group: a transmutation from a reference (i.e., a pointer with provenance) to one without (e.g., a "raw" pointer) or to a `usize` number cannot be safe. (Rust can safely provide these conversions via the `as` keyword, just not via the more general framework of transmutations).

More broadly: Rust is very sensitive to LLVM bugs that inadvertently generate UB. The longstanding issues with `noalias` optimizations is the prime example of this: https://stackoverflow.com/a/57259339/7501301