[lld] [lld][ELF][test] Accept zlib-ng compressed size (PR #206880)

[Mark Zhuang via llvm-commits]

zqb-all wrote:

With Claude's help analyzing this, the issue is unrelated to RISC-V: zlib-ng on x86 produces the larger size too, because at level 1 zlib-ng deliberately uses deflate_quick, a speed-for-ratio tradeoff.

https://github.com/llvm/llvm-project/pull/206880