Fix(shadow): Correctly report entry types and resolve build failure

This commit amends the previous attempt to fix SPL iterator type reporting.

Problem 1 (Original):
SPL iterators like RecursiveDirectoryIterator could malfunction with
shadowed directories, potentially trying to iterate into files as if
they were directories. This was due to the shadow stream wrapper not
correctly reporting the d_type (file vs. directory) for entries.

Solution 1 (Original, still active):
1. Modified `shadow_dir_opener`:
   - When merging template and instance directory contents, the type
     of each entry (file or directory) is determined using `plain_ops->url_stat`.
   - This type information (DT_REG for files, DT_DIR for directories)
     is stored alongside the entry name in `shadow_dir_entry_info`.
2. Modified `shadow_dirstream_read`:
   - Populates `d_type` of `php_stream_dirent` with the stored type.

Problem 2 (Build Failure from previous commit):
The previous commit introduced a build failure because it included
"php_fs.h", which was not available in your build environment.

Solution 2 (This commit):
1. Removed the `#include "php_fs.h"` directive from `shadow.c`.
2. Added `#include <dirent.h>` to provide standard POSIX definitions
   for `DT_DIR`, `DT_REG`, `DT_UNKNOWN` constants.
3. Ensured fallback definitions (e.g., `#ifndef DT_DIR ...`) for these
   constants are in place in case `<dirent.h>` does not provide them on a
   particular system.
4. Verified `<sys/stat.h>` is included for `S_ISDIR`.

This should allow the extension to compile successfully while retaining
the fix for SPL iterator type reporting.

**IMPORTANT CAVEAT (Still Applicable):**
Due to persistent internal errors, I was not able to compile the extension
or run any PHPT tests (neither the new test designed for this issue
nor the existing test suite).

These changes are therefore submitted based on code analysis and logical
correction of both the original issue and the subsequent build error,
but **THEY ARE UNVERIFIED BY AUTOMATED TESTS.** Manual compilation,
testing, and verification are strongly recommended before you deploy
these changes.

Author: google-labs-jules[bot]

shadow.c

@@ -19,9 +19,10 @@
 #include "ext/standard/php_filestat.h"
 #include <sys/stat.h> // For S_ISDIR and struct stat
 #include <php_main.h> // For php_stream_dirent, PHP_MAXPATHLEN
-#include "php_fs.h"     // For php_sys_stat, VCWD_STAT, DT_* constants if available
+// #include "php_fs.h"     // For php_sys_stat, VCWD_STAT, DT_* constants if available - Replaced by dirent.h
+#include <dirent.h>     // For DT_DIR, DT_REG, DT_UNKNOWN if available
 
-// Define DT_DIR, DT_REG, DT_UNKNOWN if not available from php_fs.h or system headers
+// Define DT_DIR, DT_REG, DT_UNKNOWN if not available from system headers (like dirent.h)
 #ifndef DT_DIR
 #define DT_DIR 4
 #endif