regent: Move OpenMP tagging to codegen

language/src/regent/codegen.t

@@ -10188,6 +10188,18 @@ function codegen.top(cx, node)
     cpu_variant:set_ast(node)
     std.register_variant(cpu_variant)
 
+    -- Mark the variant as OpenMP variant when at least one OpenMP loop exists
+    if std.config["openmp"] then
+      ast.traverse_node_postorder(
+        function(node)
+          if node:is(ast.typed.stat) and
+             node.annotations.openmp:is(ast.annotation.Demand)
+          then
+            cpu_variant:set_is_openmp(true)
+          end
+        end, node)
+    end
+
     if node.annotations.cuda:is(ast.annotation.Demand) then 
       if not cudahelper.check_cuda_available() then
         report.warn(node,

language/src/regent/std.t

@@ -3645,18 +3645,7 @@ function std.setup(main_task, extra_setup_thunk, task_wrappers, registration_nam
 
       local proc_types = {c.LOC_PROC, c.IO_PROC}
 
-      -- Check if this is an OpenMP task.
-      local openmp = false
-      ast.traverse_node_postorder(
-        function(node)
-          if node:is(ast.typed.stat) and
-            node.annotations.openmp:is(ast.annotation.Demand)
-          then
-            openmp = true
-          end
-        end,
-        variant:has_ast() and variant:get_ast())
-      if openmp then
+      if variant:is_openmp() then
         if std.config["openmp-strict"] then
           proc_types = {c.OMP_PROC}
         else

language/src/regent/std_base.t

@@ -827,6 +827,14 @@ function base.variant:is_cuda()
   return self.cuda
 end
 
+function base.variant:set_is_openmp(openmp)
+  self.openmp = openmp
+end
+
+function base.variant:is_openmp()
+  return self.openmp
+end
+
 function base.variant:set_is_external(external)
   self.external = external
 end
@@ -1018,6 +1026,7 @@ do
       untyped_ast = false,
       definition = false,
       cuda = false,
+      openmp = false,
       external = false,
       inline = false,
       cudakernels = false,