Add check for cuf kernel loop number exceeding do concurrent index range, and add a test for it

Author: wangzpgi

flang/test/Semantics/cuf09.cuf

@@ -133,6 +133,10 @@ program main
   !$cuf kernel do <<< 1, 2 >>>
   do concurrent (j=1:10)
   end do
+  !ERROR: !$CUF KERNEL DO (2) must be followed by a DO construct with tightly nested outer levels of counted DO loops
+  !$cuf kernel do(2) <<< 1, 2 >>>
+  do concurrent (j=1:10)
+  end do
   !$cuf kernel do <<< 1, 2 >>>
   do 1 j=1,10
 1 continue ! ok