fix for the __kmpc_global_num_threads function to return the value of the __kmp_all_nth global var

[yanyh]

Summary

As the comments and the function name indicate, the function returns the internal global num of a thread, not the num of a thread within a team, which is what the current function do by returning the value of kmp_nth global var. This patch fixes that by returning the kmp_all_nth value.

[AndreyChurbanov]

LGTM

Yonghong, you are right, the kmp_all_nth counts all threads created by the runtime library, whereas kmp_nth counts only active threads those belong to OMP teams.

openmp/trunk/runtime/src/kmp_csupport.cpp

 called from more than one non-OpenMP thread, and this reflects the total over all such calls.
 Similarly the runtime maintains underlying threads even when they are not active (since the cost
 of creating and destroying OS threads is high), this call counts all such threads even if they are not
 waiting for work.
 */
 kmp_int32
 __kmpc_global_num_threads(ident_t *loc)
 {
-    KC_TRACE( 10, ("__kmpc_global_num_threads: num_threads = %d\n", __kmp_nth ) );
+    KC_TRACE(10,("__kmpc_global_num_threads: num_threads = %d\n", __kmp_all_nth));
 
-    return TCR_4(__kmp_nth);
+    return TCR_4(__kmp_all_nth);
 }
 
 /*!
 @ingroup THREAD_STATES
 @param loc Source location information.
 @return The thread number of the calling thread in the innermost active parallel construct.
 
 */