Support/PathV2: Add remove_filename implementation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120513 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/PathV2.cpp b/lib/Support/PathV2.cpp
index a97f3ec..df401bd 100644
--- a/lib/Support/PathV2.cpp
+++ b/lib/Support/PathV2.cpp
@@ -503,6 +503,14 @@
   return make_error_code(errc::success);
 }
 
+error_code remove_filename(SmallVectorImpl<char> &path) {
+  size_t end_pos = parent_path_end(StringRef(path.begin(), path.size()));
+  if (end_pos == StringRef::npos)
+    return make_error_code(errc::success);
+  path.set_size(end_pos);
+  return make_error_code(errc::success);
+}
+
 }
 }
 }