Kernel: Remove trap based syscall handling

This patch removes the x86 mechanism for calling syscalls, favoring
the more modern syscall instruction. It also moves architecture
dependent code from functions that are meant to be architecture
agnostic therefore paving the way for adding more architectures.

Kernel/Arch/x86_64/SyscallEntry.cpp

@@ -4,9 +4,18 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <Kernel/API/Syscall.h>
 #include <Kernel/Arch/TrapFrame.h>
 #include <Kernel/Arch/x86_64/DescriptorTable.h>
 #include <Kernel/Arch/x86_64/Processor.h>
+#include <Kernel/Assertions.h>
+#include <Kernel/Panic.h>
+#include <Kernel/Process.h>
+#include <Kernel/Scheduler.h>
+#include <Kernel/Thread.h>
+#include <Kernel/ThreadTracer.h>
+
+using namespace Kernel;
 
 extern "C" void syscall_entry();
 extern "C" [[gnu::naked]] void syscall_entry()

Kernel/Arch/x86_64/init.cpp

@@ -341,7 +341,6 @@ void init_stage2(void*)
     }
 
     NetworkingManagement::the().initialize();
-    Syscall::initialize();
 
 #ifdef ENABLE_KERNEL_COVERAGE_COLLECTION
     (void)KCOVDevice::must_create().leak_ref();