Fix unused function build error in lld

The lld-x86_64-darwin13 is failing with:
 error: unused function 'operator<<'

Wrap the declation in ifndef NDEBUG, which matches
what is done in MipsELFObjectWriter.cpp.

Differential Revision: https://reviews.llvm.org/D34384

llvm-svn: 305771

llvm/lib/MC/WasmObjectWriter.cpp

@@ -162,10 +162,12 @@ struct WasmRelocationEntry {
 #endif
 };
 
+#if !defined(NDEBUG)
 raw_ostream &operator<<(raw_ostream &OS, const WasmRelocationEntry &Rel) {
   Rel.print(OS);
   return OS;
 }
+#endif
 
 class WasmObjectWriter : public MCObjectWriter {
   /// Helper struct for containing some precomputed information on symbols.