ee8b035fab
Bump compiler_builtins Actually closes https://github.com/rust-lang/rust/issues/108489. Note that the example code given [in compiler_builtins](https://github.com/rust-lang/compiler-builtins/pull/527) doesn't compile on current rustc since we're still waiting for https://reviews.llvm.org/D153197 (aka `LLVM ERROR: Expected a constant shift amount!`), but it's a step forward anyway.