af2f8a8c14
Introduce a fresh analysis for recognizing polynomial hashes, with the rationale that several targets have specific instructions to optimize things like CRC and GHASH (eg. X86 and RISC-V crypto extension). We limit the scope to polynomial hashes computed in a Galois field of characteristic 2, since this class of operations can also be optimized in the absence of target-specific instructions to use a lookup table. At the moment, we only recognize the CRC algorithm. RFC: https://discourse.llvm.org/t/rfc-new-analysis-for-polynomial-hash-recognition/86268