[llvm] [Exegesis][RISCV] Support C_LDSP for llvm-exegesis (PR #169660)

[Craig Topper via llvm-commits]

topperc wrote:

Does the rest of llvm-exegesis need to know that we're accessing stack instead of the scratch memory it set up? If the offset is too large, can't it cause the stack access to page fault?

https://github.com/llvm/llvm-project/pull/169660