[Orc] Use MapperJITLinkMemoryManager with InProcessMapper in llvm-jitlink tool

MapperJITLinkMemoryManager has slab allocation. Combined with
InProcessMapper, it can replace InProcessMemoryManager.

It can also replace JITLinkSlabAllocator through the InProcessDeltaMapper
that adds an offset to the executor addresses for use in tests.

Differential Revision: https://reviews.llvm.org/D132315