Ext2FS: Make reported file_type values match up with those in dirent

This fixes an issue we had in the git port where git would not
recognize untracked files (for example in 'git status').
When git used readdir, the 'd_type' field in the dirent struct contained
bad values (Specifically, it contained the values defiend in
Kernel/FileSystem/ext2_fs.h instead of the ones in LibC/dirent.h).

After this fix, we can create a new git repository with 'git init', and
then stage and commit files as usual.

Kernel/UnixTypes.h

@@ -614,3 +614,25 @@ struct rtentry {
 #define PT_PEEK 7
 #define PT_POKE 8
 #define PT_SETREGS 9
+
+// Used in struct dirent
+enum {
+    DT_UNKNOWN = 0,
+#define DT_UNKNOWN DT_UNKNOWN
+    DT_FIFO = 1,
+#define DT_FIFO DT_FIFO
+    DT_CHR = 2,
+#define DT_CHR DT_CHR
+    DT_DIR = 4,
+#define DT_DIR DT_DIR
+    DT_BLK = 6,
+#define DT_BLK DT_BLK
+    DT_REG = 8,
+#define DT_REG DT_REG
+    DT_LNK = 10,
+#define DT_LNK DT_LNK
+    DT_SOCK = 12,
+#define DT_SOCK DT_SOCK
+    DT_WHT = 14
+#define DT_WHT DT_WHT
+};