Move kernel symbolication code out of init.cpp and into its own KSym files.

Also use a simple array of { dword, const char* } for the KSyms and put the
whole shebang in kmalloc_eternal() memory. This was a fugly source of
kmalloc perma-frag.

Kernel/KSyms.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <AK/AKString.h>
+#include <AK/Vector.h>
+
+struct KSym {
+    dword address;
+    const char* name;
+};
+
+const KSym* ksymbolicate(dword address) PURE;
+void load_ksyms();
+
+extern bool ksyms_ready;
+extern dword ksym_lowest_address;
+extern dword ksym_highest_address;