Avoid static initialization of recursive mutexes

There is no portable way to statically initialize recursive mutexes.
Where possible avoid doing so, and where not possible add a specialized
__constructor__ (thanks @eschnett for the patch).

Fixes #12029.

Signed-off-by: George Bosilca <bosilca@icl.utk.edu>

Author: bosilca

ompi/instance/instance.c

@@ -59,7 +59,14 @@
 
 ompi_predefined_instance_t ompi_mpi_instance_null = {{{{0}}}};
 
+#if defined(OPAL_RECURSIVE_MUTEX_STATIC_INIT)
 static opal_recursive_mutex_t instance_lock = OPAL_RECURSIVE_MUTEX_STATIC_INIT;
+#else
+static opal_recursive_mutex_t instance_lock;
+__attribute__((__constructor__)) static void instance_lock_init(void) {
+    OBJ_CONSTRUCT(&instance_lock, opal_recursive_mutex_t);
+}
+#endif  /* defined(OPAL_RECURSIVE_MUTEX_STATIC_INIT) */
 
 /** MPI_Init instance */
 ompi_instance_t *ompi_mpi_instance_default = NULL;

opal/mca/btl/usnic/btl_usnic_component.c

@@ -83,7 +83,7 @@
 #define OPAL_BTL_USNIC_NUM_COMPLETIONS 500
 
 /* MPI_THREAD_MULTIPLE_SUPPORT */
-opal_recursive_mutex_t btl_usnic_lock = OPAL_RECURSIVE_MUTEX_STATIC_INIT;
+opal_recursive_mutex_t btl_usnic_lock;  /* recursive mutexes must be dynamically initialized */
 
 /* RNG buffer definition */
 opal_rng_buff_t opal_btl_usnic_rand_buff = {{0}};