[llvm] [LoopIdiom] Use costing to determine CRC strategy (PR #211040)

[Piotr Fusik via llvm-commits]

pfusik wrote:

> The easiest thing to do would be to once again disable CRC optimization as a whole for optsize, since the only platform where clmul seems to reduce the code size in most cases is RISC-V.

Yes, KISS.

https://github.com/llvm/llvm-project/pull/211040