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

[Mark Zhuang via llvm-commits]

zqb-all wrote:

I encountered this issue while building and running LLVM tests on a RISC-V platform. The chip is a SpacemiT K3, and the OS is Bianbu—a Ubuntu-based distribution that ships with zlib-ng by default.
```
bianbu at k3-deb1-25:/mnt/nvme/llvm/build$ STD=/tmp/zlibstd/usr/lib/riscv64-linux-gnu
bianbu at k3-deb1-25:/mnt/nvme/llvm/build$ ldd ./bin/ld.lld | grep libz
        libz.so.1 => /usr/lib/riscv64-linux-gnu/libz.so.1 (0x0000003faf2e1000)
bianbu at k3-deb1-25:/mnt/nvme/llvm/build$ ls -l /usr/lib/riscv64-linux-gnu/libz.so.1
lrwxrwxrwx 1 root root 21 Jan 21 16:12 /usr/lib/riscv64-linux-gnu/libz.so.1 -> libz.so.1.3.1.zlib-ng
bianbu at k3-deb1-25:/mnt/nvme/llvm/build$ LD_LIBRARY_PATH=$STD ldd ./bin/ld.lld | grep libz
        libz.so.1 => /tmp/zlibstd/usr/lib/riscv64-linux-gnu/libz.so.1 (0x0000003f9d0d5000)
bianbu at k3-deb1-25:/mnt/nvme/llvm/build$ ls -l $STD/libz.so.1
lrwxrwxrwx 1 bianbu bianbu 13 Jan 23 19:24 /tmp/zlibstd/usr/lib/riscv64-linux-gnu/libz.so.1 -> libz.so.1.3.1
bianbu at k3-deb1-25:/mnt/nvme/llvm/build$ D=tools/lld/test/ELF/Output; mkdir -p $D
bianbu at k3-deb1-25:/mnt/nvme/llvm/build$ ./bin/yaml2obj /mnt/nvme/llvm/lld/test/ELF/compressed-debug-level.test -o $D/x.o
bianbu at k3-deb1-25:/mnt/nvme/llvm/build$ ./bin/ld.lld $D/x.o -o $D/x.ng  --compress-debug-sections=zlib 2>/dev/null
bianbu at k3-deb1-25:/mnt/nvme/llvm/build$ echo -n "zlib-ng   : "; ./bin/llvm-readelf --sections $D/x.ng  | awk '/debug_info/{print $7}'
zlib-ng   : 000020
bianbu at k3-deb1-25:/mnt/nvme/llvm/build$ LD_LIBRARY_PATH=$STD ./bin/ld.lld $D/x.o -o $D/x.std --compress-debug-sections=zlib 2>/dev/null
bianbu at k3-deb1-25:/mnt/nvme/llvm/build$ echo -n "std zlib  : "; ./bin/llvm-readelf --sections $D/x.std | awk '/debug_info/{print $7}'
std zlib  : 00001e
```

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