core/memory: Migrate over memory mapping functions to the new Memory class

Migrates all of the direct mapping facilities over to the new memory
class. In the process, this also obsoletes the need for memory_setup.h,
so we can remove it entirely from the project.

src/core/CMakeLists.txt

@@ -509,7 +509,6 @@ add_library(core STATIC
     memory/dmnt_cheat_vm.h
     memory.cpp
     memory.h
-    memory_setup.h
     perf_stats.cpp
     perf_stats.h
     reporter.cpp