The jar path was defined as classpath variable but was never provided.
In order to have a clean environment state with all variables properly
defined (and so allow automatic checks for the invalid variables), added
jclFull1.8src.zip as a copy of jclMin1.8src.zip.

Note: it was not possible to find out how jclFull1.8src was originally
constructed, so here we simply copy jclMin1.8src.

See https://github.com/eclipse-jdt/eclipse.jdt.core/issues/2536