repro_common should do all the comparison work in _CP directory

[sxa]

What are you trying to do? Run the reproducible build comparison scripts in tooling/reproducible

Expected behaviour: Original directories (such as my original GA builds) are not modified when the comparisons are made.

Observed behaviour: Original directories are used for all the processing, archive expansion and other deletions .

Any other comments: The _CP directories are created, but these are only used for executing the original parts of the JDK that are required. This is the wrong way round - the new _CP ones should be used for all the temporary work required for the comparison and the original directories should be untouched.

[judovana]

This is one of the reasons I created the: #4008 so there is something, which always do a copy before all the destruction starts.