fix issue 10752 - accessing a private cached symbol a second time
doesn't cause an error in __traits(compiles, ...)
Merge pull request #2448 from hpohl/10752

fix issue 10752 - accessing a private cached symbol a second time doesn't cause an error in __traits(compiles, ...)
revert pull #2454
Merge pull request #2468 from WalterBright/revert2454

revert pull #2454