[llvm-cov] Disable zlib compression in a test input, unbreaks bots

Disable name compression in the inputs used to produce
multiple-files.covmapping. Should fix bots which don't compile with
zlib:

  http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/19610/steps/test/logs/stdio

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280898 91177308-0d34-0410-b5e6-96231b3b80d8

Author: vedantk