Supress a gcc-4.3 warning.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53771 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index c664546..a8b4905 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -1138,7 +1138,7 @@
   
   if (EnablePRE) {
     bool PREChanged = false;
-    while (PREChanged = performPRE(F))
+    while ((PREChanged = performPRE(F)))
       changed |= PREChanged;
   }