Remove musttail definition in test.cpp

src/test.cpp

@@ -118,16 +118,6 @@
 
 namespace {
 
-#ifndef __has_attribute
-#define __has_attribute(x) 0
-#endif
-
-#if __has_attribute(musttail)
-#define MUSTTAIL __attribute__((musttail))
-#else
-#define MUSTTAIL
-#endif
-
 const std::string json = R"({
     "a number": 12345,
     "true": true,