modify json-c default build type, and fix up the assert() errors in testcase

tests/CMakeLists.txt

@@ -52,8 +52,3 @@ target_link_libraries(
 
 endforeach(TESTNAME)
 
-# Make sure NDEBUG is always undefined for tests
-if (UNIX OR MINGW OR CYGWIN)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -UNDEBUG")
-endif()
-

tests/test_deep_copy.c

@@ -2,7 +2,12 @@
 #include <stdlib.h>
 #include <stddef.h>
 #include <string.h>
+#ifdef NDEBUG
+#undef NDEBUG
 #include <assert.h>
+#else
+#include <assert.h>
+#endif
 #include <errno.h>
 #include <time.h>
 

tests/test_json_pointer.c

@@ -1,6 +1,11 @@
 #include "strerror_override.h"
 #include "strerror_override_private.h"
+#ifdef NDEBUG
+#undef NDEBUG
 #include <assert.h>
+#else
+#include <assert.h>
+#endif
 #include <stdio.h>
 #include <string.h>