Revert "[cmake] Use `GNUInstallDirs` to support custom installation dirs."

https://lab.llvm.org/buildbot/#/builders/46/builds/21146 Still have
this odd error, not sure how to reproduce, so I will just try breaking
up my patch.

This reverts commit 4a678f8072004eff9214c1a4e1836a14abb69535.

GitOrigin-RevId: da77db58d7629a3bfea1a0053aa9c29764b0bc2b
1 file changed
tree: 880f9258936e9cb10407f6b79e17410d7d81c3cf
  1. cmake/
  2. docs/
  3. include/
  4. src/
  5. test/
  6. .clang-format
  7. CMakeLists.txt
  8. LICENSE.TXT