[test] Use libside rather then the somewhat confusing liblib. NFC (#25825)

Author: sbc100

test/core/pthread/test_pthread_dlopen_many.c

@@ -30,7 +30,7 @@ void* thread_main(void* arg) {
   while (thread_count != NUM_THREADS) {}
 
   char filename[255];
-  sprintf(filename, "liblib%d.so", num);
+  sprintf(filename, "libside%d.so", num);
   printf("loading %s\n", filename);
   void* handle = dlopen(filename, RTLD_NOW|RTLD_GLOBAL);
   printf("done loading %s (total=%d)\n", filename, ++dso_count);

test/core/pthread/test_pthread_dlsym.c

@@ -10,7 +10,7 @@ func_t g_two;
 func_t g_three;
 
 void* open_lib() {
-  void* handle = dlopen("liblib.so", RTLD_NOW|RTLD_GLOBAL);
+  void* handle = dlopen("libside.so", RTLD_NOW|RTLD_GLOBAL);
   if (!handle) {
     printf("dlerror: %s\n", dlerror());
     assert(handle);

test/core/pthread/test_pthread_dylink_entry_point.c

@@ -7,7 +7,7 @@ typedef void* (*thread_main_t)(void*);
 int main() {
   puts("hello from main");
 
-  void *lib_handle = dlopen("./liblib.so", RTLD_NOW);
+  void *lib_handle = dlopen("./libside.so", RTLD_NOW);
   if (!lib_handle) {
     puts("cannot load side module");
     puts(dlerror());