Not to besmirch Pony (I think it's a very interesting language), but isn't some of this a base sampling error? There are probably a few orders of magnitude more engineers writing Rust (and therefore running `rustc`), so we'd expect crashes in Rust to surface more frequently.
I'm not sure I understand. Rust is memory safe, and the memory unsafety happening here isn't in Rust itself: an IR generation bug in Rust is causing memory unsafety in LLVM, which is written in C++.
(Besides: If GitHub's stats are correct, `ponyc` seems to be >60% C and C++?)
Compilers for memory safe languages written in the same memory safe languages should be expected to have to same guarantees as any other program written in that language