[lld] [lld][LoongArch] Relax R_LARCH_PCALA_HI20 and R_LARCH_PCALA_LO12 (PR #112696)

[Lu Weining via llvm-commits]

SixWeining wrote:

All commits in one PR will be squashed and merged, so you'd better rewrite the commit message in the first commit.

https://github.com/llvm/llvm-project/pull/112696