AU: When checking if we've visited a file before, don't follow symlinks.

test_utils.cc

Index: test_utils.cc
diff --git a/test_utils.cc b/test_utils.cc
index 3815d7bfabc76ca9dc35e4fb68f082e21b8ff388..85c73d73950eccf676d13713fab3cde718ad5096 100644
--- a/test_utils.cc
+++ b/test_utils.cc
@@ -211,12 +211,15 @@ void CreateExtImageAtPath(const string& path, vector<string>* out_paths) {
   EXPECT_EQ(0, System(StringPrintf("echo T > %s/srchardlink0", kMountPath)));
   EXPECT_EQ(0, System(StringPrintf("ln %s/srchardlink0 %s/srchardlink1",
                                    kMountPath, kMountPath)));
+  EXPECT_EQ(0, System(StringPrintf("ln -s bogus %s/boguslink",
+                                   kMountPath)));
   EXPECT_EQ(0, System(StringPrintf("umount -d %s", kMountPath)));
 
   if (out_paths) {
     out_paths->clear();
     out_paths->push_back("");
     out_paths->push_back("/hi");
+    out_paths->push_back("/boguslink");
     out_paths->push_back("/hello");
     out_paths->push_back("/some_dir");
     out_paths->push_back("/some_dir/empty_dir");