[AArch64][SME]: Generate streaming-compatible code for fp-compares.

To generate code compatible to streaming mode:
 - enable expanding ISD::SETUEQ to avoid custom-lowering setcc to setcc_merge_zero
   which cause a crash while instruction selection because there is no pattern match for it.

- Testing files:
 - fp-compares.ll

Differential Revision: https://reviews.llvm.org/D138670