org.eclipse.jdt.internal.compiler.batch.ClasspathJrt.allModules()

Access to module names maps stored in ModulesCache must be synchronized,
because it is used from global static context and is not MT safe.

Change-Id: I3f6b5e478070a1e2de8d9431fdf43a3513085677
Signed-off-by: Andrey Loskutov <loskutov@gmx.de>