vfs: remove more unused VirtualFD code

Remove additional unused code from VirtualFD class:
- get position() / set position() - never accessed
- get flags() - never accessed
- kFlags symbol - no longer needed
- flags parameter from constructor and openVirtualFd()

fd.js reduced from 162 to 87 lines.

PR-URL: #61478

Author: mcollina

lib/internal/vfs/fd.js

@@ -8,7 +8,6 @@ const {
 // Private symbols
 const kFd = Symbol('kFd');
 const kEntry = Symbol('kEntry');
-const kFlags = Symbol('kFlags');
 
 // FD range: 10000+ to avoid conflicts with real fds
 const VFS_FD_BASE = 10_000;
@@ -25,12 +24,10 @@ class VirtualFD {
   /**
    * @param {number} fd The file descriptor number
    * @param {VirtualFileHandle} entry The virtual file handle
-   * @param {string} flags The open flags (r, r+, w, w+, a, a+)
    */
-  constructor(fd, entry, flags) {
+  constructor(fd, entry) {
     this[kFd] = fd;
     this[kEntry] = entry;
-    this[kFlags] = flags;
   }
 
   /**
@@ -48,41 +45,16 @@ class VirtualFD {
   get entry() {
     return this[kEntry];
   }
-
-  /**
-   * Gets the current position.
-   * @returns {number}
-   */
-  get position() {
-    return this[kEntry].position;
-  }
-
-  /**
-   * Sets the current position.
-   * @param {number} pos The new position
-   */
-  set position(pos) {
-    this[kEntry].position = pos;
-  }
-
-  /**
-   * Gets the open flags.
-   * @returns {string}
-   */
-  get flags() {
-    return this[kFlags];
-  }
 }
 
 /**
  * Opens a virtual file and returns its file descriptor.
  * @param {VirtualFileHandle} entry The virtual file handle
- * @param {string} flags The open flags
  * @returns {number} The file descriptor
  */
-function openVirtualFd(entry, flags) {
+function openVirtualFd(entry) {
   const fd = nextFd++;
-  const vfd = new VirtualFD(fd, entry, flags);
+  const vfd = new VirtualFD(fd, entry);
   openFDs.set(fd, vfd);
   return fd;
 }

lib/internal/vfs/file_system.js

@@ -597,7 +597,7 @@ class VirtualFileSystem {
   openSync(filePath, flags = 'r', mode) {
     const providerPath = this._toProviderPath(filePath);
     const handle = this[kProvider].openSync(providerPath, flags, mode);
-    return openVirtualFd(handle, flags);
+    return openVirtualFd(handle);
   }
 
   /**
@@ -803,7 +803,7 @@ class VirtualFileSystem {
     const providerPath = this._toProviderPath(filePath);
     this[kProvider].open(providerPath, flags, mode)
       .then((handle) => {
-        const fd = openVirtualFd(handle, flags);
+        const fd = openVirtualFd(handle);
         callback(null, fd);
       })
       .catch((err) => callback(err));