Add a check for pthread_setname_np with three parameters

As found in NetBSD.

CMakeLists.txt

@@ -623,6 +623,16 @@ int main()
 }"
                 PTHREAD_SETNAME_NP_ONE_PARAM
             )
+            CHECK_C_SOURCE_COMPILES("
+#include <pthread.h>
+#include <pthread_np.h>
+int main()
+{
+    pthread_setname_np(pthread_self(), \"%s\", \"testname\");
+    return 0;
+}"
+                PTHREAD_SETNAME_NP_THREE_PARAMS
+            )
         ENDIF()
         CHECK_SYMBOL_EXISTS(pthread_mutexattr_setkind_np "pthread.h;pthread_np.h" HAVE_PTHREAD_MUTEXATTR_SETKIND_NP)
     ELSE()
@@ -639,6 +649,15 @@ int main()
 }"
                 PTHREAD_SETNAME_NP_ONE_PARAM
             )
+            CHECK_C_SOURCE_COMPILES("
+#include <pthread.h>
+int main()
+{
+    pthread_setname_np(pthread_self(), \"%s\", \"testname\");
+    return 0;
+}"
+                PTHREAD_SETNAME_NP_THREE_PARAMS
+            )
         ENDIF()
         CHECK_SYMBOL_EXISTS(pthread_mutexattr_setkind_np pthread.h HAVE_PTHREAD_MUTEXATTR_SETKIND_NP)
     ENDIF()

common/threads.c

@@ -500,6 +500,8 @@ void althrd_setname(althrd_t thr, const char *name)
 #if defined(PTHREAD_SETNAME_NP_ONE_PARAM)
     if(althrd_equal(thr, althrd_current()))
         pthread_setname_np(name);
+#elif defined(PTHREAD_SETNAME_NP_THREE_PARAMS)
+    pthread_setname_np(thr, "%s", (void*)name);
 #else
     pthread_setname_np(thr, name);
 #endif

config.h.in

@@ -197,6 +197,9 @@
 /* Define if pthread_setname_np() only accepts one parameter */
 #cmakedefine PTHREAD_SETNAME_NP_ONE_PARAM
 
+/* Define if pthread_setname_np() accepts three parameters */
+#cmakedefine PTHREAD_SETNAME_NP_THREE_PARAMS
+
 /* Define if we have pthread_set_name_np() */
 #cmakedefine HAVE_PTHREAD_SET_NAME_NP