[llvm] [RISCV][TTI] Implement getAddressComputationCost() in RISCV TTI. (PR #149955)

[Elvis Wang via llvm-commits]

ElvisWang123 wrote:


After #150371 landed, the potential regression is gone ([5db0a39](https://github.com/llvm/llvm-project/pull/149955/commits/5db0a39d39933bb46b225ce0eef5e03ebd7a4eef))

https://github.com/llvm/llvm-project/pull/149955