[kernel] Remove explicit allocator passing

Many kernel objects had to keep a hold of refrences to allocators in
order to pass them on down the call chain. Remove those explicit
refrences and use `operator new`, `operator delete`, and define new
`kalloc` and `kfree`.

Also remove `slab_allocator` and replace it with a new mixin for slab
allocation, `slab_allocated`, that overrides `operator new` and
`operator free` for its subclass.

Remove some no longer used related headers, `buddy_allocator.h` and
`address_manager.h`

Tags: memory

src/kernel/scheduler.h

@@ -4,7 +4,6 @@
 
 #include <stdint.h>
 #include "kutil/allocator.h"
-#include "kutil/slab_allocator.h"
 #include "process.h"
 
 class lapic;
@@ -31,8 +30,7 @@ public:
 
 	/// Constructor.
 	/// \arg apic  Pointer to the local APIC object
-	/// \arg alloc Allocator to use for TCBs
-	scheduler(lapic *apic, kutil::allocator &alloc);
+	scheduler(lapic *apic);
 
 	/// Create a new process from a program image in memory.
 	/// \arg name  Name of the program image
@@ -86,9 +84,6 @@ private:
 	uint32_t m_next_pid;
 	uint32_t m_tick_count;
 
-	using process_slab = kutil::slab_allocator<process>;
-	process_slab m_process_allocator;
-
 	process_node *m_current;
 	process_list m_runlists[num_priorities];
 	process_list m_blocked;