Update LLVM for 3.5 rebase (r209712).

Change-Id: I149556c940fb7dc92d075273c87ff584f400941f
diff --git a/lib/Bitcode/Reader/BitstreamReader.cpp b/lib/Bitcode/Reader/BitstreamReader.cpp
index 1fd9abd..f31e1fa 100644
--- a/lib/Bitcode/Reader/BitstreamReader.cpp
+++ b/lib/Bitcode/Reader/BitstreamReader.cpp
@@ -315,7 +315,7 @@
   if (EnterSubBlock(bitc::BLOCKINFO_BLOCK_ID)) return true;
 
   SmallVector<uint64_t, 64> Record;
-  BitstreamReader::BlockInfo *CurBlockInfo = 0;
+  BitstreamReader::BlockInfo *CurBlockInfo = nullptr;
 
   // Read all the records for this module.
   while (1) {