dart:io | Add FileSystemEntity.typeSync to test for symbolic links.

runtime/bin/file_linux.cc

Index: runtime/bin/file_linux.cc
diff --git a/runtime/bin/file_linux.cc b/runtime/bin/file_linux.cc
index 459a69271a4f0055c0850da10d746ac525003ab3..ce0ef27bb26c5ea84f21e13424b345098c4d2f4e 100644
--- a/runtime/bin/file_linux.cc
+++ b/runtime/bin/file_linux.cc
@@ -246,4 +246,20 @@ File::StdioHandleType File::GetStdioHandleType(int fd) {
   return kOther;
 }
 
+
+File::Type File::GetType(const char* pathname, bool follow_links) {
+  struct stat entry_info;
+  int stat_success;
+  if (follow_links) {
+    stat_success = TEMP_FAILURE_RETRY(stat(pathname, &entry_info));
+  } else {
+    stat_success = TEMP_FAILURE_RETRY(lstat(pathname, &entry_info));
+  }
+  if (stat_success == -1) return File::kDoesNotExist;
+  if (S_ISDIR(entry_info.st_mode)) return File::kIsDirectory;
+  if (S_ISREG(entry_info.st_mode)) return File::kIsFile;
+  if (S_ISLNK(entry_info.st_mode)) return File::kIsLink;
+  return File::kDoesNotExist;
+}
+
 #endif  // defined(TARGET_OS_LINUX)