Update slang for LLVM 3.5 rebase (r209713).

Change-Id: If0f510085358d2e48c865257851d9ff7f5846eb8
diff --git a/llvm-rs-cc.cpp b/llvm-rs-cc.cpp
index d26eb63..40209e0 100644
--- a/llvm-rs-cc.cpp
+++ b/llvm-rs-cc.cpp
@@ -515,7 +515,7 @@
                               llvm::SmallVectorImpl<const char*> &ArgVector,
                               std::set<std::string> &SavedStrings) {
   const char *FName = Arg + 1;
-  llvm::OwningPtr<llvm::MemoryBuffer> MemBuf;
+  std::unique_ptr<llvm::MemoryBuffer> MemBuf;
   if (llvm::MemoryBuffer::getFile(FName, MemBuf)) {
     // Unable to open the file
     ArgVector.push_back(SaveStringInSet(SavedStrings, Arg));