- fixed JRE version in launch config
- fixed pom setup
- fixed classloading clash if loading classes from
org.eclipse.ant.tests.core.support package. The "support" classes must
be loaded by AntClassLoader, not by EquinoxClassLoader, otherwise they
have parent class loaded by Equinox that can't be casted to same class
loaded by Ant class loader.

Change-Id: Ifdd61241c0bce987598b476863593e459f52ed2c
Signed-off-by: Andrey Loskutov <loskutov@gmx.de>
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform/+/183570
Tested-by: Platform Bot <platform-bot@eclipse.org>