Add a way to initialize VFS globals.

This is needed since the kernel loader doesn't even zero out bss,
much less call any static constructors.

VirtualFileSystem/FileSystem.cpp

@@ -2,16 +2,22 @@
 #include <AK/HashMap.h>
 #include "FileSystem.h"
 
-static dword s_lastFileSystemID = 0;
+static dword s_lastFileSystemID;
+static HashMap<dword, FileSystem*>* map;
 
 static HashMap<dword, FileSystem*>& fileSystems()
 {
-    static HashMap<dword, FileSystem*>* map;
     if (!map)
         map = new HashMap<dword, FileSystem*>();
     return *map;
 }
 
+void FileSystem::initializeGlobals()
+{
+    s_lastFileSystemID = 0;
+    map = 0;
+}
+
 FileSystem::FileSystem()
     : m_id(++s_lastFileSystemID)
 {

VirtualFileSystem/FileSystem.h

@@ -18,6 +18,7 @@ static const dword mepoch = 476763780;
 
 class FileSystem : public Retainable<FileSystem> {
 public:
+    static void initializeGlobals();
     virtual ~FileSystem();
 
     dword id() const { return m_id; }

VirtualFileSystem/VirtualFileSystem.cpp

@@ -7,6 +7,11 @@
 
 //#define VFS_DEBUG
 
+void VirtualFileSystem::initializeGlobals()
+{
+    FileSystem::initializeGlobals();
+}
+
 static dword encodedDevice(unsigned major, unsigned minor)
 {
     return (minor & 0xff) | (major << 8) | ((minor & ~0xff) << 12);

VirtualFileSystem/VirtualFileSystem.h

@@ -14,6 +14,8 @@ class FileSystem;
 
 class VirtualFileSystem {
 public:
+    static void initializeGlobals();
+
     struct Node {
         InodeIdentifier inode;