Fix another isFirstClassType that now needs to be isSingleValueType.
This fixes recent CBE regressions.

llvm-svn: 51483
diff --git a/llvm/lib/Target/CBackend/CBackend.cpp b/llvm/lib/Target/CBackend/CBackend.cpp
index 4473af1..251b9f9 100644
--- a/llvm/lib/Target/CBackend/CBackend.cpp
+++ b/llvm/lib/Target/CBackend/CBackend.cpp
@@ -913,7 +913,7 @@
            << *CE << "\n";
       abort();
     }
-  } else if (isa<UndefValue>(CPV) && CPV->getType()->isFirstClassType()) {
+  } else if (isa<UndefValue>(CPV) && CPV->getType()->isSingleValueType()) {
     Out << "((";
     printType(Out, CPV->getType()); // sign doesn't matter
     Out << ")/*UNDEF*/";