Extract trampoline code into a separate file

xtoskrnl/ar/i686/boot.S

@@ -0,0 +1,14 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/ar/i686/boot.S
+ * DESCRIPTION:     i686-specific boot code for setting up the low-level CPU environment
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
+ */
+
+#include <amd64/asmsup.h>
+
+.altmacro
+.text
+
+