Revert "[RISCV] Prefer SP over FP for frame index access when offset fits within compressed immediate range. (#193962)" (#201041)
This reverts commits:
* 46e07d38e078799fa83386ef2b3b5ee423a467c5
* b5d577d3faef34276991fe80b5f869e3f8ef7442
This change is causing a miscompile in zstd, see the discussion under
https://github.com/llvm/llvm-project/pull/193962 for more details.