TableGen: Use StringRef instead of const std::string& in return vals.

This will allow to switch to a different string storage in an upcoming
commit.

llvm-svn: 288612
diff --git a/llvm/utils/TableGen/DisassemblerEmitter.cpp b/llvm/utils/TableGen/DisassemblerEmitter.cpp
index 44815b0..6e1d8dd 100644
--- a/llvm/utils/TableGen/DisassemblerEmitter.cpp
+++ b/llvm/utils/TableGen/DisassemblerEmitter.cpp
@@ -104,7 +104,7 @@
 
 void EmitDisassembler(RecordKeeper &Records, raw_ostream &OS) {
   CodeGenTarget Target(Records);
-  emitSourceFileHeader(" * " + Target.getName() + " Disassembler", OS);
+  emitSourceFileHeader(" * " + Target.getName().str() + " Disassembler", OS);
 
   // X86 uses a custom disassembler.
   if (Target.getName() == "X86") {