Use dwarf writer to decide whether the module has debug info or not.

llvm-svn: 62184
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
index 88c96ba..d79e6aa 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
@@ -4984,3 +4984,9 @@
 unsigned DwarfWriter::getRecordSourceLineCount() {
   return DD->getRecordSourceLineCount();
 }
+
+/// hasDebugInfo - Return true if debug info intrinsics are seen in 
+/// this module.
+bool DwarfWriter::hasDebugInfo() {
+  return DD && DD->ShouldEmitDwarf();
+}