[SimpleLoopUnswitch] Increment stats counter for unswitching switch instruction

Increment statistics counter NumSwitches at unswitchNontrivialInvariants() for
unswitching a non-trivial switch instruction. This is to fix a bug that it
increments NumBranches even for the case of switch instruction.
There is no functional change in this patch.

Differential Revision: https://reviews.llvm.org/D56408

llvm-svn: 351193

llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp

@@ -2281,7 +2281,10 @@ static void unswitchNontrivialInvariants(
   if (MSSAU && VerifyMemorySSA)
     MSSAU->getMemorySSA()->verifyMemorySSA();
 
-  ++NumBranches;
+  if (BI)
+    ++NumBranches;
+  else
+    ++NumSwitches;
 }
 
 /// Recursively compute the cost of a dominator subtree based on the per-block