Mark these two classes as hidden, shrinking libllbmgcc.dylib by 25K


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28970 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 3961606..241801c 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -35,6 +35,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Target/TargetLowering.h"
+#include "llvm/Support/Visibility.h"
 #include <algorithm>
 #include <cmath>
 #include <iostream>
@@ -43,7 +44,7 @@
 namespace {
   Statistic<> NodesCombined ("dagcombiner", "Number of dag nodes combined");
 
-  class DAGCombiner {
+  class VISIBILITY_HIDDEN DAGCombiner {
     SelectionDAG &DAG;
     TargetLowering &TLI;
     bool AfterLegalize;