Auto merge of #2989 - eduardosm:x86-intrinsics, r=RalfJung

miri: implement some `llvm.x86.sse.*` intrinsics and add tests

PR moved from rust-lang/rust#113932.

Implements LLVM intrisics needed to run most SSE functions from `core::arch::x86{,_64}`.

Also adds miri tests for those functions (mostly copied from core_arch tests).

r? `@RalfJung`

The first commit is the same that the commit in the PR I had opened in the Rust repository. I addressed review comments in additional commits to make it easier to review. I also fixed formatting and clippy warnings.

Author: bors