There are a lot of inline-asm related bugs in the compiler. I'm hitting them almost daily (I'm writing a kernel, so a fair bit of asm is going on here). You can see them in the bug tracker[0].

Stabilizing inline asm in its current form would be a mistake. It's simply not ready.

[0]: https://github.com/rust-lang/rust/issues?q=is%3Aopen+is%3Ais...