See if this fixes llvm-gcc bootstrap.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124184 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index c8a3ae8..98b4489 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -742,7 +742,8 @@
     // If X and Y are both non-negative (as signed values) then their sum is not
     // zero.
     if (XKnownNonNegative && YKnownNonNegative)
-      return true;
+      return false;
+//      return true;
 
     // If X and Y are both negative (as signed values) then their sum is not
     // zero unless both X and Y equal INT_MIN.