OpenMP: Add omp_in_explicit_task to omp_runtime_api_call

gcc/
	* omp-low.cc (omp_runtime_api_call): Add omp_runtime_api_call.

diff --git a/gcc/omp-low.cc b/gcc/omp-low.cc
index 9757592c635..1818132830f 100644
--- a/gcc/omp-low.cc
+++ b/gcc/omp-low.cc
@@ -4082,6 +4082,7 @@ omp_runtime_api_call (const_tree fndecl)
       "get_thread_num",
       "get_wtick",
       "get_wtime",
+      "in_explicit_task",
       "in_final",
       "in_parallel",
       "init_lock",