Use llvm::copy. NFC

llvm-svn: 347126
diff --git a/llvm/lib/Support/Path.cpp b/llvm/lib/Support/Path.cpp
index 7eba596..a3e6941 100644
--- a/llvm/lib/Support/Path.cpp
+++ b/llvm/lib/Support/Path.cpp
@@ -533,7 +533,7 @@
 
   // If prefixes have the same size we can simply copy the new one over.
   if (OldPrefix.size() == NewPrefix.size()) {
-    std::copy(NewPrefix.begin(), NewPrefix.end(), Path.begin());
+    llvm::copy(NewPrefix, Path.begin());
     return;
   }