* Implement GetMallocUsage to get usage of malloc heap
* Implement GetMemoryUsage to get total memory usage of process
* Implement GetTimeUsage to get elapsed/user/system time
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19055 91177308-0d34-0410-b5e6-96231b3b80d8