[llvm] [Mips] Fix expsensive_check test failure when x86 run readcyclecounte… (PR #127775)

[YunQiang Su via llvm-commits]

wzssyqa wrote:

What's is real do should be in the commit msg subject instead of where we find it.
Such as

MIPS: RegisterInfo Reserved HWR2

Mention what it resolved in the description part of commit msg.

https://github.com/llvm/llvm-project/pull/127775