Add implementation file.

Author: sunfishcode

libc-bottom-half/sources/__wasilibc_dt.c

@@ -0,0 +1,32 @@
+#include <__header_dirent.h>
+#include <__mode_t.h>
+
+int __wasilibc_iftodt(int x) {
+    switch (x) {
+        case S_IFDIR: return DT_DIR;
+        case S_IFCHR: return DT_CHR;
+        case S_IFBLK: return DT_BLK;
+        case S_IFREG: return DT_REG;
+        case S_IFIFO: return DT_FIFO;
+        case S_IFLNK: return DT_LNK;
+#ifdef DT_SOCK
+        case S_IFSCK: return DT_SOCK;
+#endif
+        case default: return DT_UNKNOWN;
+    }
+}
+
+int __wasilibc_dttoif(int x) {
+    switch (x) {
+        case DT_DIR: return S_IFDIR;
+        case DT_CHR: return S_IFCHR;
+        case DT_BLK: return S_IFBLK;
+        case DT_REG: return S_IFREG;
+        case DT_FIFO: return S_IFIFO;
+        case DT_LNK: return S_IFLNK;
+#ifdef DT_SOCK
+        case DT_SOCK: return S_IFSCK;
+#endif
+        case DT_UNKNOWN: return S_IFSCK;
+    }
+}