IfConversion: Fix bug introduced by rescanning diamonds.

Passing the wrong values for predicate-clobbering. Simple to miss.
Added an assert to make this easier to catch in the future.

llvm-svn: 280517
diff --git a/llvm/lib/CodeGen/IfConversion.cpp b/llvm/lib/CodeGen/IfConversion.cpp
index 76b4f34..3f74ff8 100644
--- a/llvm/lib/CodeGen/IfConversion.cpp
+++ b/llvm/lib/CodeGen/IfConversion.cpp
@@ -1982,7 +1982,7 @@
   if (!IfConvertDiamondCommon(
       BBI, TrueBBI, FalseBBI,
       NumDups1, NumDups2,
-      TrueBBI.ClobbersPred, FalseBBI.ClobbersPred,
+      TClobbersPred, FClobbersPred,
       /* RemoveBranch */ TrueBBI.IsBrAnalyzable,
       /* MergeAddEdges */ TailBB == nullptr))
     return false;