Compile fix

include/grpc/impl/codegen/port_platform.h

@@ -409,10 +409,15 @@ typedef unsigned __int64 uint64_t;
 #define CENSUSAPI GRPCAPI
 #endif
 
+#ifndef GPR_ATTRIBUTE_NO_TSAN  // (1)
 #if defined(__has_feature)
 #if __has_feature(thread_sanitizer)
 #define GPR_ATTRIBUTE_NO_TSAN __attribute__((no_sanitize("thread")))
-#endif
+#endif                         // __has_feature(thread_sanitizer)
-#endif
+#endif                         // defined(__has_feature)
+#ifndef GPR_ATTRIBUTE_NO_TSAN  // (2)
+#define GPR_ATTRIBUTE_NO_TSAN
+#endif  // GPR_ATTRIBUTE_NO_TSAN (2)
+#endif  // GPR_ATTRIBUTE_NO_TSAN (1)
 
 #endif /* GRPC_IMPL_CODEGEN_PORT_PLATFORM_H */