Any other code in the Eclipse that submits long-running or blocking
tasks to the common pool can starve the search workers, and vice versa.
A slow search can degrade or block unrelated framework work that also
relies on the common pool (e.g. parallel streams, CompletableFuture).

The new dedicated ForkJoinPool is inspired by
org.eclipse.core.internal.filesystem.local.LocalFile.FILE_SERVICE
implementation.

See https://github.com/eclipse-jdt/eclipse.jdt.ui/issues/2994