[llvm] [LoongArch] Allow delayed decision for ADD/SUB relocations (PR #72960)

[Fangrui Song via llvm-commits]

================
@@ -0,0 +1,68 @@
+# RUN: llvm-mc --filetype=obj --triple=loongarch64 --mattr=-relax < %s \
----------------
MaskRay wrote:

omit `< ` for llvm-mc.

https://github.com/llvm/llvm-project/pull/72960