8230020: [BACKOUT] compiler/types/correctness/* tests fail with "assert(recv == __null || recv->is_klass()) failed: wrong type" Summary: Back out JDK-8225670 due to performance regressions. Reviewed-by: roland

* The "clangd" indexer must be present in PATH, or configured with "clangd.path" in user preferences.
* If building with clang (default on OSX), precompiled headers must be disabled.