[llvm] [Mips] Add MipsPat `add $gp, (select $cond, tglobaladdr, tglobaladdr)` to parse MipsISD::GPRel TargetGlobalAddress (PR #165531)

[Brad Smith via llvm-commits]

brad0 wrote:

> It's not obvious to me what the problem being solved here is from the description.

Look at the bug report mentioned.

https://github.com/llvm/llvm-project/pull/165531