[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/tests/address_manager.cpp

@@ -1,78 +0,0 @@
-#include <chrono>
-#include <random>
-#include <vector>
-#include <stddef.h>
-#include <stdlib.h>
-#include <stdint.h>
-
-#include "kutil/address_manager.h"
-#include "kutil/allocator.h"
-#include "catch.hpp"
-
-using namespace kutil;
-
-static const size_t max_block = 1ull << 36;
-static const size_t start = max_block;
-static const size_t GB = 1ull << 30;
-
-class malloc_allocator :
-	public kutil::allocator
-{
-public:
-	virtual void * allocate(size_t n) override { return malloc(n); }
-	virtual void free(void *p) override { free(p); }
-};
-
-TEST_CASE( "Buddy addresses tests", "[address buddy]" )
-{
-	malloc_allocator alloc;
-	address_manager am(alloc);
-	am.add_regions(start, max_block * 2);
-
-	// Blocks should be:
-	// 36: 0-64G, 64-128G
-
-	uintptr_t a = am.allocate(0x400); // under min
-	uintptr_t b = am.allocate(0x400);
-	CHECK( b == a + address_manager::min_alloc);
-
-	am.free(a);
-	am.free(b);
-
-	// Should be back to
-	// 36: 0-64G, 64-128G
-
-	a = am.allocate(max_block);
-	CHECK(a == start);
-	am.free(a);
-
-	// Should be back to
-	// 36: 0-64G, 64-128G
-
-	// This should allocate the 66-68G block, not the
-	// 66-67G block.
-	a = am.mark( start + 66 * GB + 0x1000, GB );
-	CHECK( a == start + 66 * GB );
-
-	// Free blocks should be:
-	// 36: 0-64G
-	// 35: 96-128G
-	// 34: 80-96G
-	// 33: 72-80G
-	// 32: 68-72G
-	// 31: 64-66G
-
-	// This should cause a split of the one 31 block, NOT
-	// be a leftover of the above mark.
-	b = am.allocate(GB);
-	CHECK( b == start + 64 * GB );
-	am.free(b);
-	am.free(a);
-
-	// Should be back to
-	// 36: 0-64G, 64-128G
-	a = am.allocate(max_block);
-	b = am.allocate(max_block);
-	CHECK( b == start + max_block );
-	CHECK( a == start );
-}