Change how File/Directory/Link .delete works.

runtime/bin/file.h

Index: runtime/bin/file.h
diff --git a/runtime/bin/file.h b/runtime/bin/file.h
index 0895a8466d37fad19e955e56e8b651e2e1c13727..ac5af00491be7cd915b1bcef0364a72d5c580754 100644
--- a/runtime/bin/file.h
+++ b/runtime/bin/file.h
@@ -76,7 +76,8 @@ class File {
     kWriteByteRequest = 15,
     kReadRequest = 16,
     kReadListRequest = 17,
-    kWriteListRequest = 18
+    kWriteListRequest = 18,
+    kDeleteLinkRequest = 19
   };
 
   ~File();
@@ -131,6 +132,7 @@ class File {
   static bool Create(const char* path);
   static bool CreateLink(const char* path, const char* target);
   static bool Delete(const char* path);
+  static bool DeleteLink(const char* path);
   static off_t LengthFromPath(const char* path);
   static time_t LastModified(const char* path);
   static char* LinkTarget(const char* pathname);