cppClean task should remove old cppdistribution contents
cppClean task should remove old cppdistribution contents

The `git clean` we used to do at the beginning of the build used to take
care of this, but due to long paths on Windows we can no longer use this

Original commit: elastic/x-pack-elasticsearch@3210c7507ba4ce1e02f521883b69fb96f6b75d04

HonzaKral/elasticsearch,vroyer/elassandra,scorpionvicky/elasticsearch,gingerwizard/elasticsearch,gingerwizard/elasticsearch,uschindler/elasticsearch,nknize/elasticsearch,GlenRSmith/elasticsearch,robin13/elasticsearch,GlenRSmith/elasticsearch,gfyoung/elasticsearch,gfyoung/elasticsearch,gfyoung/elasticsearch,robin13/elasticsearch,nknize/elasticsearch,strapdata/elassandra,scorpionvicky/elasticsearch,HonzaKral/elasticsearch,strapdata/elassandra,gingerwizard/elasticsearch,nknize/elasticsearch,uschindler/elasticsearch,uschindler/elasticsearch,strapdata/elassandra,coding0011/elasticsearch,scorpionvicky/elasticsearch,nknize/elasticsearch,robin13/elasticsearch,scorpionvicky/elasticsearch,coding0011/elasticsearch,coding0011/elasticsearch,uschindler/elasticsearch,HonzaKral/elasticsearch,GlenRSmith/elasticsearch,coding0011/elasticsearch,robin13/elasticsearch,gingerwizard/elasticsearch,strapdata/elassandra,gingerwizard/elasticsearch,GlenRSmith/elasticsearch,strapdata/elassandra,vroyer/elassandra,vroyer/elassandra,gfyoung/elasticsearch,gingerwizard/elasticsearch,scorpionvicky/elasticsearch,coding0011/elasticsearch,gingerwizard/elasticsearch,HonzaKral/elasticsearch,GlenRSmith/elasticsearch,nknize/elasticsearch,uschindler/elasticsearch,gfyoung/elasticsearch,robin13/elasticsearch