[OpenACC] Don't restrict ACC wait arguments to constants in fortran

[Cesar Philippidis]

I noticed that gfortran complains when the integer wait queue argument
for the acc wait directive is not a constant value. That's an odd
restriction, that not even the wait clause enforces. Considering that
this patch is one-liner, I've committed this patch to trunk as obvious
to remove this restriction.

I'll backport this patch to og7 shortly.

Cesar

2017-09-21  Cesar Philippidis  <ce...@codesourcery.com>

	gcc/fortran/
	* openmp.c (gfc_match_oacc_wait): Don't restrict wait directive
	arguments to constant integers.

	gcc/testsuite/
	* gfortran.dg/goacc/wait.f90: New test.


diff --git a/gcc/fortran/openmp.c b/gcc/fortran/openmp.c
index 8400354181c..c5e00888bbe 100644
--- a/gcc/fortran/openmp.c
+++ b/gcc/fortran/openmp.c
@@ -2185,8 +2185,7 @@ gfc_match_oacc_wait (void)
 	  }
 
 	if (!gfc_resolve_expr (el->expr)
-	    || el->expr->ts.type != BT_INTEGER || el->expr->rank != 0
-	    || el->expr->expr_type != EXPR_CONSTANT)
+	    || el->expr->ts.type != BT_INTEGER || el->expr->rank != 0)
 	  {
 	    gfc_error ("WAIT clause at %L requires a scalar INTEGER expression",
 		       &el->expr->where);
diff --git a/gcc/testsuite/gfortran.dg/goacc/wait.f90 b/gcc/testsuite/gfortran.dg/goacc/wait.f90
new file mode 100644
index 00000000000..9cdbcdf822e
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/goacc/wait.f90
@@ -0,0 +1,12 @@
+! Ensure that ACC WAIT accept integer arguments.
+
+subroutine foo (wqueue)
+  implicit none
+  integer :: wqueue, waitno
+  integer, parameter :: waitp = 100
+
+  !$acc wait (wqueue)
+  !$acc wait (waitno)
+  !$acc wait (waitp)
+  !$acc wait (0)
+end subroutine foo