Validate debug info values only if DwarfDebug is initialized.

llvm-svn: 62298
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
index 5e98618..ab66887 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
@@ -4272,7 +4272,7 @@
 
 /// ValidDebugInfo - Return true if V represents valid debug info value.
 bool DwarfWriter::ValidDebugInfo(Value *V) {
-  return DD->ValidDebugInfo(V);
+  return DD && DD->ValidDebugInfo(V);
 }
 
 /// RecordSourceLine - Records location information and associates it with a