Allow for switch with no cases.  Was causing fault
in gcc.dg/pr27531-1.c.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51464 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp
index 9c17b77..79cda33 100644
--- a/lib/Transforms/Scalar/SCCP.cpp
+++ b/lib/Transforms/Scalar/SCCP.cpp
@@ -1379,6 +1379,8 @@
       if (!getValueState(BI->getCondition()).isUndefined())
         continue;
     } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
+      if (SI->getNumSuccessors()<2)   // no cases
+        continue;
       if (!getValueState(SI->getCondition()).isUndefined())
         continue;
     } else {