[clang] [CIR][test] Use global instcombine RUN line in AArch64 neon subtracti… (PR #207894)

[Jiahao Guo via cfe-commits]

https://github.com/E00N777 approved this pull request.

LGTM (I will wait for the current PR to be merged before handling https://github.com/llvm/llvm-project/pull/207189)

https://github.com/llvm/llvm-project/pull/207894