Revert "Fix hmaptool cmake file to work on Windows"

This reverts commit 63711c3cd337a0d22617579a904af07481139611, due to
breaking bots:

http://lab.llvm.org:8011/builders/clang-x64-ninja-win7/builds/11315
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/10411/steps/test-check-all/logs/stdio

llvm-svn: 335194