[tests] Add annotations for taskloop features

[Hahnfeld]

Summary

Only supported since GCC 6 and Intel 17.0. However GCC 6.3.0 is
crashing on two of the tests, so disable them as well...

[AndreyChurbanov]

LGTM

runtime/test/ompt/tasks/taskloop.c

 // RUN: %libomp-compile-and-run | FileCheck %s
 // RUN: %libomp-compile-and-run | FileCheck --check-prefix=TASKS %s
 // REQUIRES: ompt
+
+// These compilers don't support the taskloop construct
+// UNSUPPORTED: gcc-4, gcc-5, icc-16
+// GCC 6 has support for taskloops, but at least 6.3.0 is crashing on this test
+// UNSUPPORTED: gcc-6
+
 #include "callback.h"
 #include <omp.h>
 
 int main() {
   unsigned int i, x;
 
 #pragma omp parallel num_threads(2)
   {

runtime/test/tasking/omp_taskloop_grainsize.c

 // RUN: %libomp-compile-and-run
 // RUN: %libomp-compile && env KMP_TASKLOOP_MIN_TASKS=1 %libomp-run
+
+// These compilers don't support the taskloop construct
+// UNSUPPORTED: gcc-4, gcc-5, icc-16
+// GCC 6 has support for taskloops, but at least 6.3.0 is crashing on this test
+// UNSUPPORTED: gcc-6
+
 /*
  * Test for taskloop
  * Method: caculate how many times the iteration space is dispatched
  *     and judge if each dispatch has the requested grainsize
  * It is possible for two adjacent chunks are executed by the same thread
  */
 #include <stdio.h>
 #include <omp.h>

runtime/test/tasking/omp_taskloop_num_tasks.c

 // RUN: %libomp-compile-and-run
 // RUN: %libomp-compile && env KMP_TASKLOOP_MIN_TASKS=1 %libomp-run
+
+// These compilers don't support the taskloop construct
+// UNSUPPORTED: gcc-4, gcc-5, icc-16
+
 /*
  * Test for taskloop
  * Method: caculate how many times the iteration space is dispatched
  *     and judge if each dispatch has the requested grainsize
  * It is possible for two adjacent chunks are executed by the same thread
  */
 #include <stdio.h>
 #include <omp.h>