ClassLoader leak in 6.0.1 Final when building incrementally

I am currently converting a Drools 5.5.0 installation to 6.0.1 Final,
due to many memory leaks in 5.5.0. Our use case involves a
knowledgebase of several thousand rules which are updated at run-time
quite frequently. As a result, we have found it necessary to do
incremental builds of rules. I based the code for this on the
integration tests:
https://github.com/droolsjbpm/drools/blob/master/drools-compiler/src/test/java/org/drools/compiler/integrationtests/IncrementalCompilationTest.java

This is working fairly well so far, but while testing, I noticed a
fairly severe increase in PermGen heap usage every time I modify my
rules.
Using jhat and the Eclipse memory analyzer, I was able to track down
the source of the problem to a classloader leak in the JavaDialect
class. Whenever a rule is added to the JavaDialect, a RuleErrorHandler
is added to an internal Map named errorHandlers. Unfortunately, this
RuleErrorHandler is never removed, and it contains a reference to a
stale PackageClassLoader. I have successfully fixed this by adding a call to this.errorHandlers.clear(); at the end of JavaDialect.compileAll().
As far as I have been able to determine, the errorHandlers map is no longer necessary at this point, and any further calls to compileAll should be preceded by updated addRule calls