Update LLVM for 3.5 rebase (r209712).

Change-Id: I149556c940fb7dc92d075273c87ff584f400941f
diff --git a/lib/MC/MCRelocationInfo.cpp b/lib/MC/MCRelocationInfo.cpp
index 7d2ec1f..a00c009 100644
--- a/lib/MC/MCRelocationInfo.cpp
+++ b/lib/MC/MCRelocationInfo.cpp
@@ -23,14 +23,14 @@
 
 const MCExpr *
 MCRelocationInfo::createExprForRelocation(object::RelocationRef Rel) {
-  return 0;
+  return nullptr;
 }
 
 const MCExpr *
 MCRelocationInfo::createExprForCAPIVariantKind(const MCExpr *SubExpr,
                                                unsigned VariantKind) {
   if (VariantKind != LLVMDisassembler_VariantKind_None)
-    return 0;
+    return nullptr;
   return SubExpr;
 }