kern: revamp KMemoryRegionType to better encode derivation hierarchies

libraries/libmesosphere/source/kern_main.cpp

@@ -51,8 +51,8 @@ namespace ams::kern {
 
             /* Initialize the memory manager and the KPageBuffer slabheap. */
             {
-                const auto &metadata_region = KMemoryLayout::GetMetadataPoolRegion();
-                Kernel::GetMemoryManager().Initialize(metadata_region.GetAddress(), metadata_region.GetSize());
+                const auto &management_region = KMemoryLayout::GetPoolManagementRegion();
+                Kernel::GetMemoryManager().Initialize(management_region.GetAddress(), management_region.GetSize());
                 init::InitializeKPageBufferSlabHeap();
             }