Changes

Bug 582724 Avoid using ThreadLocal in f-j pool

due to change in jdk17 to automatically clear ThreadLocals from FJ pool threads, a
relatively large amount of memory accumulates during initial parsing since the
task block threadlocals never got large enough to flush

switch away from ThreadLocal which does come with a mild performance impact but
keeps the app running

Task-Url: https://bugs.eclipse.org/bugs/show_bug.cgi?id=582724
Change-Id: If0fda91d14f78b5b74928aac215a34a34823571b