Fix PR2358 by resolving calls with undef arguments to overdefined.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51535 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/SCCP.cpp

@@ -1370,6 +1370,12 @@ bool SCCPSolver::ResolvedUndefsIn(Function &F) {
         else
           markOverdefined(LV, I);
         return true;
+      case Instruction::Call:
+        // If a call has an undef result, it is because it is constant foldable
+        // but one of the inputs was undef.  Just force the result to
+        // overdefined.
+        markOverdefined(LV, I);
+        return true;
       }
     }