Use StringRef instead of std::string in DIEString.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89793 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 4ba156c..f8873a4 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -333,7 +333,7 @@
 /// addString - Add a string attribute data and value.
 ///
 void DwarfDebug::addString(DIE *Die, unsigned Attribute, unsigned Form,
-                           const std::string &String) {
+                           const StringRef String) {
   DIEValue *Value = new DIEString(String);
   DIEValues.push_back(Value);
   Die->addValue(Attribute, Form, Value);