Shrink libllvmgcc.dylib by another 23K

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28972 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Utils/Mem2Reg.cpp

@@ -20,12 +20,13 @@
 #include "llvm/Function.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/Support/Visibility.h"
 using namespace llvm;
 
 namespace {
   Statistic<> NumPromoted("mem2reg", "Number of alloca's promoted");
 
-  struct PromotePass : public FunctionPass {
+  struct VISIBILITY_HIDDEN PromotePass : public FunctionPass {
     // runOnFunction - To run this pass, first we calculate the alloca
     // instructions that are safe for promotion, then we promote each one.
     //