kernel: Make size argument to create_area_etc() size_t.

It was limited to a uint32 and could for example be overflown by the
slab MemoryManager that uses size_t on a 64 bit system.

This aligns the signature with create_area() that already uses size_t
for the size argument.

Note that the function is currently private, so the impact should be
limited.

headers/private/kernel/vm/vm.h

@@ -76,7 +76,7 @@ void permit_page_faults(void);
 void forbid_page_faults(void);
 
 // private kernel only extension (should be moved somewhere else):
-area_id create_area_etc(team_id team, const char *name, uint32 size,
+area_id create_area_etc(team_id team, const char *name, size_t size,
 			uint32 lock, uint32 protection, uint32 flags, uint32 guardSize,
 			const virtual_address_restrictions* virtualAddressRestrictions,
 			const physical_address_restrictions* physicalAddressRestrictions,

src/system/kernel/vm/vm.cpp

@@ -6079,7 +6079,7 @@ clone_area(const char* name, void** _address, uint32 addressSpec,
 
 
 area_id
-create_area_etc(team_id team, const char* name, uint32 size, uint32 lock,
+create_area_etc(team_id team, const char* name, size_t size, uint32 lock,
 	uint32 protection, uint32 flags, uint32 guardSize,
 	const virtual_address_restrictions* virtualAddressRestrictions,
 	const physical_address_restrictions* physicalAddressRestrictions,