[llvm] [X86] Prefer andl to andb to save one byte encoding when using with bzhi or bextr (PR #86921)

[Craig Topper via llvm-commits]

topperc wrote:

> * As I mentioned above, it is considered beneficial for bzhi/bextr, which matches with GCC;

It's been a long time since I looked, but I thought gcc generally avoids 8 bit registers. Not just for bzhi/bextr.

https://github.com/llvm/llvm-project/pull/86921