[llvm] [BOLT] Delete unnecessary instructions (PR #189297)

[YongKang Zhu via llvm-commits]

yozhu wrote:

> @yozhu Could you please review this PR?

Hello @WangJee, thanks for the PR. Unfortunately I'm not familiar with RISC-V ISA and ABI. Maybe wait for someone with more RISCV experience to take a look?

https://github.com/llvm/llvm-project/pull/189297