HANG drcachesim on win10 1903

On my win10 1903 machine, the 64-bit drcachesim tests all timeout. It looks like the app run under drcachesim exits mysteriously during DR initialization. I was going to try to repro #3320 on this machine but apparently it has even worse problems.

When I attach windbg to the app at the start message, it stays up: but I can't break into the app! It's like the debugger is now hung too.