Add a VFS::absolutePath(InodeIdentifier).

This is pretty inefficient for ext2fs. We walk the entire block group
containing the inode, searching through every directory for an entry
referencing this inode.

It might be a good idea to cache this information somehow. I'm not sure
how often we'll be searching for it.

Obviously there are multiple caching layers missing in the file system.

VirtualFileSystem/SyntheticFileSystem.cpp

@@ -199,7 +199,7 @@ Unix::ssize_t SyntheticFileSystem::readInodeBytes(InodeIdentifier inode, Unix::o
 #endif
     ASSERT(offset >= 0);
     ASSERT(buffer);
-\
+
     auto it = m_inodes.find(inode.index());
     if (it == m_inodes.end())
         return false;
@@ -235,3 +235,11 @@ auto SyntheticFileSystem::generateInodeIndex() -> InodeIndex
 {
     return m_nextInodeIndex++;
 }
+
+InodeIdentifier SyntheticFileSystem::findParentOfInode(InodeIdentifier inode) const
+{
+    auto it = m_inodes.find(inode.index());
+    if (it == m_inodes.end())
+        return { };
+    return (*it).value->parent;
+}