Fix file locking for PROXYFS nodes that wrap NODEFS (#2437)

## Motivation for the change, related issues

File locking isn't applying to SQLite DB when a real directory is
mounted as `/wordpress`. It looks like this happens for PROXYFS nodes
that wrap NODEFS nodes.

Fixes #2427

## Implementation details

This PR fixes PROXYFS lookups of original NODEFS nodes so we can check
whether a node is for a shared FS or for MEMFS.

This PR also fills in two unimplemented FileLockManagerForNode tests and
adds them to the `test-asyncify` and `test-jspi` targets for the
php-wasm-node project.

While fixing the tests, I noticed a couple of whole-file locking where
locks were allowed where macOS's locking implementation would have
denied them (fcntl() and flock() locks held by the same process can
conflict). IIUC, Linux may not deny locks in those cases, but I've tried
to lean toward being more restrictive rather than more permissive when
it comes to granting locks.

## Testing Instructions (or ideally a Blueprint)

- New unit tests that test file locking behavior for proxied and
unproxied NODEFS and MEMFS nodes.

Author: brandonpayton

packages/php-wasm/compile/php/esm-suffix.js

@@ -60,19 +60,16 @@ if (typeof NODEFS === 'object') {
     // We override NODEFS.createNode() to add an `isSharedFS` flag to all NODEFS
     // nodes. This way we can tell whether file-locking is needed and possible
     // for an FS node, even if wrapped with PROXYFS.
-    const originalCreateNode = NODEFS.createNode;
+    const originalNodeFsCreateNode = NODEFS.createNode;
     NODEFS.createNode = function createNodeWithSharedFlag() {
-        const node = originalCreateNode.apply(NODEFS, arguments);
+        const node = originalNodeFsCreateNode.apply(NODEFS, arguments);
         node.isSharedFS = true;
         return node;
     };
 
     var originalHashAddNode = FS.hashAddNode;
     FS.hashAddNode = function hashAddNodeIfNotSharedFS(node) {
-        if (
-            typeof locking === 'object' &&
-            locking?.is_shared_fs_node(node)
-        ) {
+        if (node?.isSharedFS) {
             // Avoid caching shared VFS nodes so multiple instances
             // can access the same underlying filesystem without
             // conflicting caches.