make the verifier accept @llvm.donothing as the only intrinsic that can be invoked
While at it, merge 2 tests and FileCheckize them

llvm-svn: 159388
diff --git a/llvm/lib/VMCore/Verifier.cpp b/llvm/lib/VMCore/Verifier.cpp
index 9a9b0b7..5d51f41 100644
--- a/llvm/lib/VMCore/Verifier.cpp
+++ b/llvm/lib/VMCore/Verifier.cpp
@@ -1636,9 +1636,11 @@
     if (Function *F = dyn_cast<Function>(I.getOperand(i))) {
       // Check to make sure that the "address of" an intrinsic function is never
       // taken.
-      CallSite CS(&I);
-      Assert1(!F->isIntrinsic() || (CS && i == (CS.isCall() ? e-1 : 2)),
+      Assert1(!F->isIntrinsic() || i == (isa<CallInst>(I) ? e-1 : 0),
               "Cannot take the address of an intrinsic!", &I);
+      Assert1(!F->isIntrinsic() || isa<CallInst>(I) ||
+              F->getIntrinsicID() == Intrinsic::donothing,
+              "Cannot invoke an intrinsinc other than donothing", &I);
       Assert1(F->getParent() == Mod, "Referencing function in another module!",
               &I);
     } else if (BasicBlock *OpBB = dyn_cast<BasicBlock>(I.getOperand(i))) {