Support/PathV2: Fix append to not add a slash to empty or root paths.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120988 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/PathV2.cpp b/lib/Support/PathV2.cpp
index 2c1d92d..73896ed 100644
--- a/lib/Support/PathV2.cpp
+++ b/lib/Support/PathV2.cpp
@@ -413,7 +413,7 @@
       continue;
     }
 
-    if (!component_has_sep && !(path.empty() && is_root_name)) {
+    if (!component_has_sep && !(path.empty() || is_root_name)) {
       // Add a separator.
       path.push_back(prefered_separator);
     }