Small eye-candy: use asciz directive everywhere, where possible.

llvm-svn: 34981
diff --git a/llvm/lib/CodeGen/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter.cpp
index 8db6a5b..4dce674 100644
--- a/llvm/lib/CodeGen/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter.cpp
@@ -559,13 +559,20 @@
 /// Special characters are emitted properly.
 /// \literal (Eg. '\t') \endliteral
 void AsmPrinter::EmitString(const std::string &String) const {
-  O << TAI->getAsciiDirective()
-    << "\"";
+  const char* AscizDirective = TAI->getAscizDirective();
+  if (AscizDirective)
+    O << AscizDirective;
+  else
+    O << TAI->getAsciiDirective();
+  O << "\"";
   for (unsigned i = 0, N = String.size(); i < N; ++i) {
     unsigned char C = String[i];
     printStringChar(O, C);
   }
-  O << "\\0\"";
+  if (AscizDirective)
+    O << "\"";
+  else
+    O << "\\0\"";
 }