DebugInfo: don't emit zero-length names for parameters

We check this in many/all other cases, just missed this one it seems.
Perhaps it'd be worth unifying this so we never emit zero-length
DW_AT_names.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188649 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 3d2c1b8..2c21142 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -1574,7 +1574,8 @@
     addDIEEntry(VariableDie, dwarf::DW_AT_abstract_origin,
                             dwarf::DW_FORM_ref4, AbsDIE);
   else {
-    addString(VariableDie, dwarf::DW_AT_name, Name);
+    if (!Name.empty())
+      addString(VariableDie, dwarf::DW_AT_name, Name);
     addSourceLine(VariableDie, DV->getVariable());
     addType(VariableDie, DV->getType());
   }