Remove some overly verbose logging.

gen/abi-x86-64.cpp

@@ -687,8 +687,11 @@ void X86_64TargetABI::rewriteFunctionType(TypeFunction* tf) {
             if (ty->ty == Tstruct)
                 fixup_D(arg);
             
+#if 0
+            // These can get pretty large...
             if (Logger::enabled())
                 Logger::cout() << "New arg type: " << *arg.ltype << '\n';
+#endif
         }
         
     } else {