malloc, so there should be no functional changes to other code.
These changes are necessary since I have plans to use this allocator in the JIT
memory manager, and it needs a special allocator.
I also added some tests which helped me pinpoint some bugs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76825 91177308-0d34-0410-b5e6-96231b3b80d8