[llvm] [DirectX][ObjectYAML] Fix SRCI round-trip tests that use zlib compression (PR #202479)

[Shoaib Meenai via llvm-commits]

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

Thank you! I see one other test failure after this:

```
FAIL: LLVM-Unit :: ObjectYAML/./ObjectYAMLTests/11/36 (2 of 68950)
******************** TEST 'LLVM-Unit :: ObjectYAML/./ObjectYAMLTests/11/36' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:$build/unittests/ObjectYAML/./ObjectYAMLTests-LLVM-Unit-4006022-11-36.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=36 GTEST_SHARD_INDEX=11 $build/unittests/ObjectYAML/./ObjectYAMLTests
--

Note: This is test shard 12 of 36.
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from DXCFile
[ RUN      ] DXCFile.ParseSRCIPart
LLVM ERROR: DXContainer SRCI Contents compressed size in header (44 bytes) doesn't match the actual compressed size (47 bytes)
```

https://github.com/llvm/llvm-project/pull/202479