[BOLT] Fix ValidateMemRefs pass (#94406)

In ValidateMemRefs pass, when we validate references in the form of
`Symbol + Addend`, we should check `Symbol` not `Symbol + Addend`
against aliasing a jump table.

Recommitting with a modified test case:
https://github.com/llvm/llvm-project/pull/88838



Co-authored-by: sinan <sinan.lin@linux.alibaba.com>