kernel/vm: Don't unset VMArea::id in delete_areas.

It's needed in delete_area for arch_vm_unset_memory_type at least.
Instead just add a parameter indicating the area is already removed
from the areas map.

src/system/kernel/vm/vm.cpp

@@ -272,7 +272,7 @@ static cache_info* sCacheInfoTable;
 
 // function declarations
 static void delete_area(VMAddressSpace* addressSpace, VMArea* area,
-	bool addressSpaceCleanup);
+	bool deletingAddressSpace, bool alreadyRemoved = false);
 static status_t vm_soft_fault(VMAddressSpace* addressSpace, addr_t address,
 	bool isWrite, bool isExecute, bool isUser, vm_page** wirePage);
 static status_t map_backing_store(VMAddressSpace* addressSpace,
@@ -2573,14 +2573,16 @@ vm_clone_area(team_id team, const char* name, void** address,
 	\param area The area to be deleted.
 	\param deletingAddressSpace \c true, if the address space is in the process
 		of being deleted.
+	\param alreadyRemoved \c true, if the area was already removed from the global
+		areas map (and thus had its ID deallocated.)
 */
 static void
 delete_area(VMAddressSpace* addressSpace, VMArea* area,
-	bool deletingAddressSpace)
+	bool deletingAddressSpace, bool alreadyRemoved)
 {
 	ASSERT(!area->IsWired());
 
-	if (area->id >= 0)
+	if (area->id >= 0 && !alreadyRemoved)
 		VMAreas::Remove(area);
 
 	// At this point the area is removed from the global hash table, but
@@ -4007,17 +4009,15 @@ vm_delete_areas(struct VMAddressSpace* addressSpace, bool deletingAddressSpace)
 	VMAreas::WriteLock();
 	{
 		VMAddressSpace::AreaIterator it = addressSpace->GetAreaIterator();
-		while (VMArea* area = it.Next()) {
+		while (VMArea* area = it.Next())
 			VMAreas::Remove(area);
-			area->id = INT32_MIN;
-		}
 	}
 	VMAreas::WriteUnlock();
 
 	// delete all the areas in this address space
 	while (VMArea* area = addressSpace->FirstArea()) {
 		ASSERT(!area->IsWired());
-		delete_area(addressSpace, area, deletingAddressSpace);
+		delete_area(addressSpace, area, deletingAddressSpace, true);
 	}
 
 	addressSpace->WriteUnlock();